Ultra Labs DL-185® Dileucine Peptide - Muscle Recovery & Performance

Human-Studied Peptide Nutrition for Muscle, Strength & Recovery

Ultra Labs DL-185® delivers 2,000mg of L-leucyl-L-leucine monohydrate (dileucine) per daily serving - an advanced dipeptide form of leucine being researched for its effects on muscle protein synthesis, strength, muscular performance and resistance-training adaptations.

Unlike standard leucine, dileucine consists of two leucine molecules bonded together as a dipeptide.

Why does that matter?

Human research comparing equal 2g doses found that dileucine significantly stimulated muscle protein synthesis, while standard leucine did not produce the same significant increase.

And the research goes beyond acute muscle protein synthesis.

In a 10-week, double-blind, placebo-controlled resistance-training study, trained males taking 2g of dileucine daily achieved greater improvements in leg-press strength compared with placebo and greater improvements in leg-press repetitions-to-failure compared with leucine.

Why Athletes Are Turning to DL-185®

⚡ Supports Muscle Protein Synthesis
Human research demonstrates an increase in muscle protein synthesis following dileucine ingestion.

💪 Supports Strength & Training Adaptation
Daily 2g dileucine supplementation has been studied alongside structured resistance training.

🔥 Supports Muscular Performance
Research has demonstrated improvements in lower-body strength and muscular endurance outcomes.

🔬 Backed by Human Research
Dileucine isn't simply another theoretical sports-nutrition ingredient — its effects have been investigated in controlled human trials.

🏋️ Built for Serious Training
Ideal for bodybuilders, strength athletes, CrossFit and hybrid athletes, and anyone wanting to maximise the results of consistent resistance training.

Full 2,000mg Daily Serving

Each 4-capsule serving of Ultra Labs DL-185® provides 2,000mg of dileucine, matching the 2g daily amount investigated in published human research.

4 CAPSULES. 2,000MG. ONCE DAILY.

Train hard. Recover. Adapt. Repeat.

What Is DL-185® Dileucine Peptide?

DL-185® is a dileucine peptide - a dipeptide consisting of two leucine molecules joined together. Its scientific name is L-leucyl-L-leucine, and it represents an emerging approach to amino-acid supplementation for athletes looking to support muscle protein synthesis, strength and resistance-training performance.

Leucine itself is one of the three branched-chain amino acids (BCAAs) and is well known for its role in signalling pathways involved in muscle protein synthesis (MPS).

Dileucine is different.

Rather than simply supplying free-form leucine, dileucine delivers two leucine molecules linked together as a peptide. Research suggests the body can absorb some dietary dipeptides intact, potentially allowing dileucine to behave differently from an equivalent dose of standard free-form leucine.

Dileucine vs Leucine: What's the Difference?

This is where DL-185® becomes particularly interesting.

In a randomized, double-blind human study, researchers compared:

2g Dileucine
vs.
2g Free-Form Leucine

Researchers measured blood amino-acid concentrations and muscle protein turnover using muscle biopsies in healthy young men.

The results showed that 2g of dileucine significantly increased muscle protein synthesis over the three-hour measurement period, while the equivalent 2g dose of free-form leucine did not significantly increase muscle protein synthesis.

Importantly, this doesn't mean leucine isn't anabolic or that dileucine will always outperform leucine at every dose.

Instead, the study demonstrates something much more interesting:

Dileucine appears to produce a different physiological response from simply consuming the same amount of leucine in free-form form.

That distinction is one of the main reasons dileucine has become an exciting emerging ingredient in sports nutrition.

More Than Just an Acute Muscle Protein Synthesis Study

Researchers have also investigated dileucine during longer-term resistance training.

In a randomized, double-blind, placebo-controlled trial, resistance-trained males consumed 2g of dileucine, 2g of leucine or placebo every day for 10 weeks while completing a four-day-per-week resistance-training program.

The dileucine group demonstrated significantly greater improvements in leg-press strength compared with placebo and greater improvements in leg-press repetitions-to-failure compared with leucine.

Not every performance or body-composition measurement differed significantly between groups, so DL-185® shouldn't be viewed as a shortcut to muscle growth.

Instead, the research suggests that dileucine may provide a valuable nutritional tool for athletes already combining progressive resistance training, adequate protein intake and proper recovery.

Why Ultra Labs DL-185® Is Different

Ultra Labs DL-185® provides:

• 2,000mg Dileucine per serving
• L-Leucyl-L-Leucine Monohydrate
• 4 capsules per daily serving
• 30 daily servings per bottle
• A simple, stimulant-free performance and recovery formula

Most importantly, the 2,000mg daily serving matches the 2g amount investigated in published human dileucine research.

DL-185® In Simple Terms

Think of it this way:

Leucine = one amino acid

Dileucine = two leucine molecules linked together as a dipeptide

That seemingly small structural difference may influence how the compound is absorbed and how it affects muscle protein metabolism.

For athletes looking beyond traditional BCAAs and standalone leucine, DL-185® represents a new generation of peptide-based sports nutrition backed by emerging human research.

How Does DL-185® Work? Dileucine, mTOR & Muscle Protein Synthesis

To understand why DL-185® Dileucine is attracting attention in sports nutrition, it helps to understand one of the most important processes involved in building and repairing muscle: muscle protein synthesis (MPS).

Muscle protein synthesis is the process your body uses to create new muscle proteins.

Resistance training provides the stimulus — but nutrition provides the amino acids and signals required to support the repair, rebuilding and adaptation process that follows.

And one amino acid plays a particularly important role in that signalling process:

Leucine.

Leucine and the mTORC1 Pathway

Leucine is widely recognised as an important nutritional signal involved in activating mTORC1 (mechanistic target of rapamycin complex 1).

Think of mTORC1 as one of the body's key cellular signalling pathways involved in regulating muscle protein synthesis.

When sufficient amino acids - particularly leucine - are available, this signalling network helps tell muscle cells that the nutritional environment is favourable for building new proteins.

This is one reason leucine-rich proteins such as whey protein have become such an important part of sports nutrition.

But DL-185® takes a different approach.

DL-185® Provides Leucine as a Dipeptide

Instead of providing individual free-form leucine molecules, dileucine consists of two leucine molecules chemically linked together as the dipeptide L-leucyl-L-leucine.

This isn't simply a different name for leucine.

Human research indicates that some ingested dileucine can appear in circulation in its intact peptide form, suggesting that dileucine has absorption and metabolic characteristics that differ from consuming the equivalent quantity of free-form leucine.

And this appears to matter when we look at muscle protein synthesis.

2g Dileucine vs 2g Leucine

In a randomized, double-blind crossover study, healthy young males consumed either:

2,000mg Dileucine

or

2,000mg Free-Form Leucine

Researchers then used blood samples, muscle biopsies and stable isotope techniques to examine what happened inside skeletal muscle over the following three hours.

Both leucine and dileucine influenced signalling proteins associated with the anabolic response.

However, there was an important difference in the actual muscle protein synthesis response.

Dileucine significantly increased cumulative muscle protein synthesis.

The equivalent 2g dose of free-form leucine did not significantly increase muscle protein synthesis during the same measurement period.

This provides evidence that the structure in which leucine is delivered may influence its effect on human muscle protein metabolism.

Why Muscle Protein Synthesis Matters

Hard training doesn't build muscle while you're actually lifting.

Resistance training creates the stimulus for adaptation.

The recovery period that follows is when your body repairs and remodels muscle tissue, and muscle protein synthesis is fundamental to that process.

Repeated periods of training followed by adequate recovery and nutrition ultimately contribute to:

• Muscle repair and remodelling
• Adaptation to resistance training
• Maintenance and development of lean muscle
• Improved ability to tolerate progressive training
• Long-term improvements in strength and performance

DL-185® should therefore be viewed as a tool for supporting this process - not as a replacement for adequate dietary protein, calories, sleep or progressive resistance training.

The DL-185® Advantage

What makes DL-185® particularly interesting isn't simply that it contains leucine.

It's how that leucine is delivered.

FREE-FORM LEUCINE
One individual leucine amino acid.

DILEUCINE
Two leucine molecules linked together as L-leucyl-L-leucine.

Human research comparing equal 2g doses found a significant muscle protein synthesis response following dileucine ingestion that wasn't observed following the same 2g quantity of free-form leucine.

That makes dileucine one of the more interesting emerging peptide-based ingredients for athletes looking to optimise the nutritional side of muscle recovery, adaptation and performance.

Ultra Labs Delivers the Human-Studied 2,000mg Dose

Ultra Labs DL-185® provides a full:

2,000mg of Dileucine per 4-capsule serving

That's particularly important because 2g is the dose used in the published human research investigating dileucine and muscle protein synthesis.

No complicated loading protocol.

No stimulants.

Just 2,000mg of human-studied dileucine per daily serving.

TRAIN → RECOVER → ADAPT → REPEAT

DL-185® for Muscle Growth & Resistance Training Adaptation

Can DL-185® help you build muscle?

The answer starts with understanding the difference between directly building muscle and supporting the biological processes that allow muscle growth to occur.

DL-185® Dileucine isn't a replacement for resistance training, adequate protein or sufficient calories.

Instead, the interest surrounding dileucine comes from its potential to support one of the fundamental processes behind muscular adaptation:

Muscle Protein Synthesis (MPS).

Muscle Growth Starts With Muscle Protein Synthesis

Every hard resistance-training session creates a stimulus for your body to adapt.

During the recovery period that follows, muscle tissue undergoes an ongoing process of breakdown, repair and remodelling.

For muscle tissue to grow over time, periods of muscle protein synthesis need to contribute to a favourable overall muscle protein balance.

This is where amino acids - and particularly leucine - become important.

Leucine is recognised as an important nutritional signal involved in regulating muscle protein synthesis.

Dileucine takes that concept one step further by providing two leucine molecules joined together as the dipeptide L-leucyl-L-leucine.

Human Research Shows Dileucine Can Stimulate Muscle Protein Synthesis

In a randomized, double-blind human trial, researchers directly compared:

2,000mg Dileucine

vs.

2,000mg Free-Form Leucine

The researchers collected muscle biopsies and used stable isotope techniques to measure muscle protein synthesis.

Over the three-hour measurement period, 2g of dileucine significantly increased cumulative muscle protein synthesis.

The equivalent 2g dose of free-form leucine did not produce a statistically significant increase under the same experimental conditions.

That's an important finding.

It suggests that delivering leucine in the form of the dileucine dipeptide may produce a different muscle protein metabolic response than simply consuming an equivalent 2g dose of free-form leucine.

But Does DL-185® Actually Build More Muscle?

This is where it's important to separate exciting research from exaggerated supplement claims.

A longer-term human study followed 34 resistance-trained males completing a structured four-day-per-week resistance-training program for 10 weeks.

Participants consumed:

2g Dileucine daily

2g Leucine daily

or

Placebo

Researchers measured numerous outcomes including body composition, muscle thickness, strength, muscular endurance and power.

Participants improved several measures over the 10 weeks of resistance training.

However, dileucine did not produce statistically significant superior increases in fat-free mass or muscle thickness compared with leucine or placebo.

So we don't believe it's accurate to tell customers that DL-185® has been clinically proven to directly produce greater muscle growth.

What the research does show is arguably more interesting.

DL-185® Improved Resistance-Training Outcomes

After 10 weeks, researchers found a significant difference between groups for lower-body strength and muscular endurance.

The dileucine group achieved a greater improvement in leg-press 1RM strength compared with placebo.

Dileucine also produced a greater improvement in leg-press repetitions-to-failure compared with leucine.

That matters for anyone interested in building muscle.

Progressive overload - gradually becoming capable of performing more work, more repetitions or moving greater loads - is one of the foundations of productive resistance training.

A supplement that supports training adaptation therefore has potential value even if it isn't directly adding kilograms of muscle by itself.

Think of DL-185® as an Adaptation Supplement

Rather than thinking:

“Take DL-185® → automatically build muscle.”

A better way to understand it is:

TRAIN HARD

↓

STIMULATE MUSCLE PROTEIN SYNTHESIS

↓

RECOVER & ADAPT

↓

GET STRONGER / INCREASE TRAINING CAPACITY

↓

PROGRESS YOUR TRAINING

↓

REPEAT

That's where DL-185® fits.

It supports the nutritional environment surrounding training and adaptation while your training, protein intake, calories and recovery continue to do the heavy lifting.

Who Could Benefit Most?

DL-185® may be particularly interesting for:

• Bodybuilders pursuing hypertrophy
• Strength athletes
• Powerlifters
• CrossFit athletes
• Hybrid athletes
• Experienced resistance trainers
• Athletes completing high training volumes
• Anyone looking to maximise recovery and adaptation from resistance training

For beginners, simply improving training quality, protein intake and sleep will generally produce the biggest returns.

For experienced athletes who already have those fundamentals covered, ingredients such as dileucine become particularly interesting because you're looking for smaller advantages that may help optimise the results of consistent training.

2,000mg of Dileucine Every Day

Ultra Labs DL-185® delivers:

2,000MG DILEUCINE

4 CAPSULES

ONCE DAILY

Importantly, 2,000mg is the same daily quantity used in the published 10-week resistance-training study.

DL-185® isn't magic.

It's something considerably more interesting:

A human-studied peptide designed to complement serious training.

DL-185® for Muscle Recovery & Post-Workout Adaptation

Training is only half of the equation.

What happens between your workouts determines how effectively your body can adapt to the work you're putting in.

Every demanding resistance-training session places stress on skeletal muscle and creates a stimulus for repair, remodelling and adaptation.

This makes recovery more than simply feeling less sore.

From a sports-nutrition perspective, recovery involves processes including muscle protein synthesis, muscle protein turnover, restoration and adaptation to repeated training.

And this is where DL-185® Dileucine becomes particularly interesting.

Supporting Muscle Protein Synthesis After Hard Training

Muscle protein synthesis (MPS) is the process through which the body produces new muscle proteins.

Resistance exercise itself stimulates MPS, while the availability of essential amino acids provides both the building blocks and nutritional signals required to support the process.

Leucine is particularly important because of its role as an anabolic signalling amino acid.

Dileucine provides leucine differently - as two leucine molecules bonded together to form the dipeptide L-leucyl-L-leucine.

Human research has demonstrated that consuming 2,000mg of dileucine significantly increased cumulative muscle protein synthesis over a three-hour measurement period.

Interestingly, an equivalent 2,000mg dose of free-form leucine did not significantly increase cumulative MPS under the same experimental conditions.

For athletes, this makes dileucine an exciting nutritional ingredient for supporting the muscle-remodelling processes associated with recovery and adaptation.

Recovery Isn't Just About Muscle Soreness

It's easy to judge recovery by one thing:

“Am I sore today?”

But DOMS - delayed onset muscle soreness - is only one subjective indication of how you feel after training.

Effective recovery is much broader.

For an athlete, the real objective is to create a cycle of:

TRAIN

↓

RECOVER

↓

ADAPT

↓

PERFORM

↓

REPEAT

Supporting muscle protein synthesis and providing adequate nutrition during this process helps create the environment your body needs to respond to repeated training.

What About DL-185® and DOMS?

You'll sometimes see dileucine promoted as a supplement for reducing DOMS or muscle soreness.

At this stage, we think it's important to distinguish between a potential recovery benefit and something that has actually been demonstrated in controlled human research.

Current published human DL-185® / dileucine research supports its effects on muscle protein synthesis and specific resistance-training performance outcomes, but the major published trials have not directly demonstrated that dileucine reduces DOMS.

For that reason, we prefer to describe DL-185® as supporting muscle recovery and training adaptation rather than claiming that it has been clinically proven to eliminate muscle soreness.

Dileucine Has Now Been Studied After Resistance Exercise

More recent human research has taken the science another step forward by investigating dileucine as part of an essential amino acid formula consumed after resistance exercise.

In a randomized, double-blind crossover study, healthy adults completed a full-body resistance-training session before consuming one of three amino-acid/protein conditions.

The dileucine-containing EAA formula provided:

2g Dileucine

1g Additional Leucine

9.15g Total Essential Amino Acids

Researchers found evidence supporting greater whole-body anabolic responses and exogenous leucine retention with the dileucine/EAA and BCAA conditions compared with collagen.

Because this study used dileucine alongside other essential amino acids, we can't attribute every result specifically to dileucine alone.

But it adds another interesting piece to the growing research surrounding dileucine and post-exercise nutrition.

Better Recovery Supports Better Training

For serious athletes, the goal isn't simply to recover from one workout.

It's to be able to consistently string together productive training sessions week after week.

That's particularly relevant for:

• Bodybuilders training each muscle group multiple times per week
• Strength athletes progressing heavy compound movements
• CrossFit and functional-fitness athletes
• Hybrid athletes combining resistance and endurance training
• Athletes completing high-volume training blocks
• Experienced lifters looking to maximise their recovery nutrition

The harder and more frequently you train, the more important your recovery strategy becomes.

That starts with the fundamentals:

Adequate Protein + Calories + Sleep + Hydration + Intelligent Programming

DL-185® can then be added as an advanced nutritional tool to complement those foundations.

2,000mg of Human-Studied Dileucine

Ultra Labs DL-185® provides:

2,000MG DILEUCINE PER SERVING

4 CAPSULES ONCE DAILY

30 SERVINGS PER BOTTLE

The 2,000mg dose isn't arbitrary.

It's the same daily dose used in published human research investigating both muscle protein synthesis and resistance-training adaptations.

For athletes who already take their training and nutrition seriously, DL-185® provides an exciting new approach to supporting what happens after the final rep:

RECOVERY → ADAPTATION → PERFORMANCE

DL-185® for Strength, Performance & Muscular Endurance

Muscle recovery is important.

But ultimately, most athletes want that recovery to translate into something measurable:

More strength. More training capacity. Better performance.

This is where the human research surrounding DL-185® Dileucine becomes particularly exciting.

Rather than only investigating what happens for several hours after taking dileucine, researchers have now studied what happens when resistance-trained athletes supplement with 2,000mg of dileucine every day while following a structured resistance-training program for 10 weeks.

And the results suggest dileucine may do considerably more than simply influence muscle protein synthesis.

The 10-Week Human Dileucine Study

In a randomized, double-blind, placebo-controlled human trial, 34 resistance-trained males were assigned to consume:

2,000mg Dileucine

vs.

2,000mg Free-Form Leucine

vs.

Placebo

every day for 10 weeks.

Importantly, these weren't sedentary individuals.

Participants were already resistance trained and completed a structured four-day-per-week resistance-training program, consisting of two upper-body and two lower-body sessions each week.

Researchers measured a range of performance outcomes including:

• Leg-press strength
• Bench-press strength
• Repetitions to failure
• Total strength
• Total repetitions
• Anaerobic performance
• Jump performance
• Force production
• Body composition

Greater Lower-Body Strength

One of the standout findings was leg-press one-repetition maximum (1RM).

After 10 weeks, the dileucine group demonstrated a significantly greater increase in maximum leg-press strength compared with placebo.

This is particularly interesting because strength development is one of the clearest indicators of successful adaptation to resistance training.

For bodybuilders, powerlifters and strength athletes, becoming capable of producing more force can help create opportunities to progressively increase training loads over time.

Greater Muscular Endurance Than Leucine

The researchers also tested muscular endurance by having participants perform repetitions to failure using 80% of their baseline 1RM.

Once again, dileucine produced an interesting result.

The dileucine group achieved a significantly greater improvement in leg-press repetitions-to-failure compared with the group taking the same 2,000mg dose of free-form leucine.

Researchers also reported a significantly greater improvement in total repetitions - leg press plus bench press - with dileucine compared with leucine.

In practical terms, this suggests dileucine may support the ability to perform more resistance-training work before reaching muscular failure.

Strength + Training Capacity

This combination is particularly interesting for serious resistance training.

MORE STRENGTH

can allow you to progressively handle heavier training loads.

GREATER MUSCULAR ENDURANCE

can potentially allow you to perform more productive repetitions and training volume.

Over weeks and months, the ability to progressively increase the demands placed on your muscles is fundamental to continued training adaptation.

That's why DL-185® shouldn't simply be thought of as another amino-acid supplement.

It represents an emerging nutritional strategy designed to complement the training process itself.

Does DL-185® Improve Every Type of Performance?

No - and this distinction matters.

The 10-week study also investigated several other measures of athletic performance, including:

• Wingate anaerobic power
• Countermovement jump performance
• Isometric force production
• Bench-press performance

Dileucine did not significantly outperform the other groups across every measurement.

So we wouldn't describe DL-185® as a universal performance enhancer that automatically makes you faster, more explosive or stronger at everything.

The strongest human evidence currently relates specifically to resistance-training adaptations, lower-body maximal strength and muscular endurance.

That's exactly where we'd expect DL-185® to be most relevant.

Who Could Benefit Most From DL-185®?

Based on the available research, DL-185® is particularly well suited to people performing regular resistance training, including:

Bodybuilders

Supporting muscle protein synthesis, recovery and the ability to continually progress resistance training.

Powerlifters & Strength Athletes

For athletes focused on increasing maximal strength and progressive overload.

CrossFit & Functional Fitness Athletes

Particularly those completing large amounts of resistance-based training volume.

Hybrid Athletes

For athletes combining resistance training with other demanding forms of exercise who want additional nutritional support for muscular adaptation.

Experienced Gym Users

Especially lifters who already have their protein intake, training program and recovery fundamentals in place and are looking for another evidence-based addition to their supplement program.

Not Another Stimulant-Based Performance Supplement

DL-185® works very differently from a pre-workout.

There's:

NO CAFFEINE

NO STIMULANTS

NO ACUTE ENERGY HIT

Instead, DL-185® is designed to support the muscular adaptation and recovery processes surrounding consistent training.

That means it can be used regardless of whether you train:

Morning. Afternoon. Night.

And it can easily sit alongside existing supplements such as protein, creatine, electrolytes or a pre-workout.

The Same 2,000mg Dose Used in Human Research

Ultra Labs DL-185® provides:

2,000MG DILEUCINE PER DAILY SERVING

That's the same daily amount used in the published 10-week resistance-training study.

For athletes who don't simply want to train hard today - but want to continue progressing their performance over weeks, months and years - that's where DL-185® becomes particularly interesting.

MORE THAN RECOVERY.

SUPPORT YOUR ABILITY TO ADAPT, PROGRESS & PERFORM.

DL-185® Dileucine vs Leucine - What's the Difference?

If leucine is already one of the most important amino acids for muscle protein synthesis, why would you take DL-185® Dileucine instead of regular leucine?

It's one of the most important questions surrounding DL-185®.

And unlike many new sports-nutrition ingredients, researchers have actually put dileucine and free-form leucine head-to-head in human studies.

The results suggest that although the two compounds are closely related, dileucine may produce effects that aren't achieved by simply consuming the same 2,000mg quantity of standard leucine.

First: What Is Leucine?

Leucine is one of the nine essential amino acids and one of the three branched-chain amino acids (BCAAs).

It's particularly important in sports nutrition because leucine acts as a nutritional signal involved in regulating the mTORC1 pathway and muscle protein synthesis (MPS).

In simple terms, leucine helps signal to muscle tissue that amino acids are available and that the machinery involved in building new muscle proteins can be activated.

That's one reason high-quality protein sources such as whey protein - which naturally contain substantial amounts of leucine - are so effective for supporting muscle recovery and growth.

So What Is Dileucine?

Dileucine is structurally different.

Instead of one individual leucine molecule, dileucine consists of two leucine molecules chemically bonded together.

Its scientific name is:

L-Leucyl-L-Leucine

This makes dileucine a dipeptide.

So although dileucine ultimately provides leucine, the body doesn't necessarily handle the peptide exactly the same way it handles an equivalent quantity of free-form leucine.

And human research suggests that difference may be important.

2,000mg Dileucine vs 2,000mg Leucine: Muscle Protein Synthesis

One of the most important dileucine studies directly compared:

2,000mg Dileucine

vs.

2,000mg Free-Form Leucine

Healthy young males consumed each treatment in a randomized crossover study while researchers collected blood samples and muscle biopsies.

The researchers found that both treatments produced similar overall plasma leucine exposure.

However, dileucine produced significantly greater circulating intact dileucine concentrations.

More importantly:

2g of dileucine significantly increased cumulative muscle protein synthesis over three hours.

The same 2g dose of free-form leucine did not significantly increase muscle protein synthesis under the same experimental conditions.

That's an extremely interesting distinction.

It suggests that simply looking at the amount of leucine contained in a supplement doesn't necessarily tell the entire story.

The form in which that leucine is delivered may matter.

What About Long-Term Training?

Researchers have also compared dileucine and leucine during 10 weeks of structured resistance training.

Resistance-trained males consumed:

2g Dileucine daily

vs.

2g Leucine daily

vs.

Placebo

while completing four resistance-training sessions per week.

After 10 weeks, the dileucine group demonstrated a significantly greater improvement in leg-press repetitions-to-failure compared with the leucine group.

Researchers also reported greater improvement in total repetitions across leg press and bench press with dileucine compared with leucine.

This provides longer-term evidence that the differences between dileucine and leucine may extend beyond an acute muscle protein synthesis response.

Is Dileucine Better Than Leucine?

This needs some context.

Based on the available research, dileucine has demonstrated advantages over an equal 2g dose of isolated free-form leucine for certain outcomes.

But that doesn't mean:

“Dileucine makes leucine obsolete.”

Leucine remains an essential amino acid and an important component of high-quality dietary protein.

The studies also compared 2g dileucine against 2g isolated leucine - they did not establish that dileucine is superior to every possible leucine dose, a complete EAA formula or an adequate serving of high-quality protein.

That's an important distinction.

The evidence instead suggests:

When equal 2g doses of isolated dileucine and isolated leucine have been directly compared, dileucine has produced some favourable outcomes that weren't observed with leucine.

Dileucine vs Leucine At a Glance

LEUCINE

• Single essential amino acid
• Important nutritional signal for muscle protein synthesis
• Naturally abundant in high-quality proteins
• Commonly found in whey protein, EAAs and BCAAs
• Extensive history in sports nutrition

DILEUCINE

• Two leucine molecules bonded together
• Also known as L-leucyl-L-leucine
• Classified as a leucine dipeptide
• Can appear in circulation in its intact peptide form
• 2g has significantly stimulated MPS in human research
• Has been directly compared with 2g leucine in human trials
• 2g/day has been investigated during 10 weeks of resistance training

Should DL-185® Replace Your Protein or EAAs?

No.

This is another important distinction.

DL-185® shouldn't be viewed as a replacement for dietary protein.

A complete protein source provides all of the essential amino acids required to actually construct new muscle proteins.

Instead, think of DL-185® as a specialised sports-nutrition ingredient that can be used alongside an adequate high-protein diet.

Your foundation should still be:

QUALITY PROTEIN

• 
  

ADEQUATE DAILY PROTEIN INTAKE

• 
  

PROGRESSIVE RESISTANCE TRAINING

• 
  

RECOVERY

DL-185® can then be layered on top as an advanced nutritional strategy.

Why Ultra Labs Uses 2,000mg

Ultra Labs DL-185® provides:

2,000MG DILEUCINE PER DAILY SERVING

This is important because 2g is the exact quantity used in both the acute human muscle-protein-synthesis study and the 10-week resistance-training trial.

So rather than simply including a token amount of an exciting new ingredient, Ultra Labs provides a dose directly aligned with the published human research.

The Bottom Line: Dileucine vs Leucine

Leucine is already one of the most important amino acids in sports nutrition.

Dileucine represents an evolution of that concept.

By linking two leucine molecules together as L-leucyl-L-leucine, researchers have created an intriguing peptide form that has now demonstrated effects on muscle protein synthesis and resistance-training performance in human studies.

The research is still emerging, and DL-185® isn't a replacement for protein, intelligent training or recovery.

But for serious athletes looking beyond traditional leucine and BCAA supplementation, dileucine represents one of the more exciting developments in peptide-based sports nutrition.

SAME LEUCINE BUILDING BLOCKS.

DIFFERENT STRUCTURE.

HUMAN-STUDIED RESULTS.

The Human Research Behind DL-185® Dileucine

One of the biggest differences between DL-185® Dileucine and many emerging sports-nutrition ingredients is that the story doesn't stop with a theoretical mechanism.

Dileucine has been investigated in controlled human research.

Studies have examined its effects on:

• Muscle protein synthesis
• Muscle protein turnover
• Resistance-training adaptations
• Maximum strength
• Muscular endurance
• Post-exercise amino-acid metabolism

Let's break down what the research actually found.

Study 1: 2g Dileucine vs 2g Leucine - Muscle Protein Synthesis

The first major human dileucine study used a randomized, double-blind crossover design involving 10 healthy young males.

Participants consumed either:

2,000mg Dileucine

or

2,000mg Free-Form Leucine

Researchers then collected repeated blood samples and muscle biopsies while using stable isotope techniques to measure muscle protein synthesis and muscle protein breakdown.

What Did Researchers Find?

Both leucine and dileucine increased circulating leucine availability.

However, dileucine produced greater circulating concentrations of intact dileucine.

Most importantly, over the three-hour measurement period:

2g Dileucine significantly increased cumulative muscle protein synthesis.

The same 2g dose of free-form leucine did not significantly increase cumulative muscle protein synthesis under these experimental conditions.

Muscle protein breakdown was not significantly different between the treatments.

Why Is This Important?

This was one of the first human demonstrations that an ingested leucine-containing dipeptide could influence human muscle protein metabolism.

It also suggests that the physical form in which leucine is delivered may matter, because equal 2g quantities of dileucine and free-form leucine didn't produce identical muscle protein synthesis responses.

Study 2: 10 Weeks of Dileucine + Resistance Training

The next major question was obvious:

What happens when athletes take dileucine every day while actually training?

Researchers investigated this in a randomized, double-blind, placebo-controlled trial involving 34 resistance-trained males.

Participants consumed:

2g Dileucine daily

2g Leucine daily

or

Placebo

for 10 weeks while completing a structured resistance-training program four days per week.

Researchers measured numerous outcomes including:

• Leg-press 1RM
• Bench-press 1RM
• Repetitions to failure
• Body composition
• Muscle thickness
• Anaerobic performance
• Jump performance
• Maximum voluntary contraction

Dileucine & Strength

After 10 weeks, the dileucine group demonstrated a significantly greater improvement in:

LEG-PRESS 1RM vs PLACEBO

This provides evidence that 2g/day of dileucine may support lower-body strength adaptations during resistance training.

Dileucine & Muscular Endurance

Researchers also found a significant advantage for dileucine in:

LEG-PRESS REPETITIONS TO FAILURE vs LEUCINE

In other words, participants taking dileucine demonstrated a greater improvement in this measure of lower-body muscular endurance than participants taking the same 2g quantity of free-form leucine.

What Didn't DL-185® Do?

This is equally important.

Dileucine did not significantly outperform the other groups across every outcome measured.

The researchers did not demonstrate a significant dileucine-specific advantage for all body-composition, muscle-thickness, strength, power or anaerobic-performance outcomes.

That means it would be misleading to say:

“DL-185® is clinically proven to build more muscle than leucine.”

The research doesn't currently establish that.

What it does provide is promising human evidence supporting muscle protein synthesis and specific resistance-training performance adaptations.

Study 3: Dileucine + EAAs After Resistance Exercise

More recently, researchers investigated dileucine in the context of post-workout amino-acid nutrition.

Twelve healthy recreationally active adults completed approximately 60 minutes of whole-body resistance exercise before consuming one of three nutritional treatments.

One treatment contained:

2g Dileucine

1g Additional Leucine

9.15g Total Essential Amino Acids

This was compared with a BCAA formula and an isonitrogenous collagen treatment.

Researchers then monitored amino-acid metabolism and several markers related to anabolism and protein turnover during the six-hour recovery period.

What Did They Find?

Exogenous leucine retention - used as an estimate of whole-body anabolism - was similar between the dileucine + EAA and BCAA treatments.

Both produced substantially greater leucine retention than collagen.

Stable-isotope measurements of mixed muscle protein synthesis showed a trend toward an overall treatment effect, with exploratory pairwise comparisons indicating a large effect for the dileucine/EAA treatment compared with collagen and a medium effect compared with BCAAs.

However, the overall condition effect for this muscle protein synthesis measurement did not reach conventional statistical significance.

An Important Distinction

This study did not test 2g dileucine by itself.

It tested dileucine as part of a complete essential-amino-acid formula.

We therefore can't attribute all of the findings specifically to dileucine.

What the study does provide is additional human research into the use of dileucine-containing nutrition during the post-resistance-exercise recovery period.

What Does the Total Research Tell Us?

When the studies are considered together, we now have human research showing that:

✓ 2g Dileucine can stimulate muscle protein synthesis

✓ Dileucine behaves differently from an equivalent 2g dose of free-form leucine

✓ 2g/day has been studied for 10 weeks alongside structured resistance training

✓ Dileucine improved leg-press strength versus placebo in that trial

✓ Dileucine improved leg-press repetitions-to-failure versus leucine

✓ Dileucine has now also been investigated alongside EAAs following resistance exercise

But the research does not currently establish that DL-185®:

✗ Automatically builds muscle without resistance training

✗ Produces greater hypertrophy than adequate protein intake

✗ Improves every measure of athletic performance

✗ Has been clinically proven to reduce DOMS

And that's exactly how we believe sports-nutrition research should be presented.

Human Studied. Not Marketing Hype.

The research surrounding dileucine is still developing.

But unlike ingredients built almost entirely around theoretical mechanisms, dileucine now has controlled human research examining both acute muscle protein metabolism and longer-term resistance-training outcomes.

That's what makes DL-185® particularly exciting.

Ultra Labs DL-185® provides:

2,000MG DILEUCINE PER DAILY SERVING

The same 2g quantity used in the published human research investigating dileucine.

For serious athletes who value supplements backed by actual research rather than hype, DL-185® represents one of the most interesting emerging developments in peptide-based sports nutrition.

HUMAN STUDIED.

RESEARCH DRIVEN.

BUILT FOR SERIOUS TRAINING.

Who Should Take DL-185® Dileucine?

Ultra Labs DL-185® is designed for people who take their training seriously and want to maximise the recovery, adaptation and performance they get from it.

Because the strongest human research surrounding dileucine currently relates to muscle protein synthesis, resistance training, strength and muscular endurance, DL-185® is particularly well suited to athletes and gym users performing regular resistance-based exercise.

Bodybuilders & Hypertrophy-Focused Lifters

If your primary goal is building muscle, your fundamentals will always come first:

Progressive Resistance Training + Adequate Protein + Calories + Recovery

DL-185® can then be added as an advanced nutritional strategy.

Human research has demonstrated that 2g of dileucine can significantly stimulate muscle protein synthesis, while longer-term research has investigated the same 2g daily dose during 10 weeks of structured resistance training.

For bodybuilders already consuming adequate protein and training consistently, DL-185® provides another way to support the processes involved in muscle recovery and adaptation.

Strength Athletes & Powerlifters

DL-185® is particularly interesting for athletes focused on getting stronger.

In the 10-week resistance-training study, participants taking 2g of dileucine daily achieved a significantly greater improvement in leg-press 1RM strength compared with placebo.

For strength athletes continually working towards progressive overload, supporting your ability to recover and adapt between demanding training sessions can be extremely valuable.

CrossFit & Functional Fitness Athletes

CrossFit and functional fitness can place enormous demands on muscular recovery.

A single training week may combine:

Heavy Resistance Training

High-Rep Strength Work

Olympic Lifting

Gymnastics

Conditioning

Repeated High-Intensity Sessions

DL-185® won't replace carbohydrates, protein, electrolytes or intelligent recovery programming.

Instead, it can complement those fundamentals by providing a human-studied dileucine dose aimed at supporting muscle protein synthesis and resistance-training adaptation.

Hybrid Athletes

Combining strength and endurance training creates a unique recovery challenge.

Running, cycling or conditioning alongside regular resistance training means your muscles are repeatedly being asked to perform, recover and adapt to different training stimuli.

DL-185® may therefore be particularly appealing to hybrid athletes looking for additional nutritional support around the resistance-training component of their program.

Importantly, current dileucine research shouldn't be interpreted as showing that DL-185® directly improves cardiovascular endurance.

Its strongest evidence relates to muscle protein metabolism and resistance-training performance.

High-Volume Trainers

Training frequently?

DL-185® becomes particularly interesting when you're completing multiple demanding resistance-training sessions every week.

This could include:

• High-volume bodybuilding programs
• Upper/lower training splits
• Push/pull/legs programs
• Strength blocks
• Multiple CrossFit sessions per week
• High-frequency resistance training
• Combined strength and conditioning programs

The goal isn't simply to recover from today's workout.

It's to support your ability to consistently train, recover, adapt and repeat.

Experienced Lifters Looking for the Next 1%

Beginners don't need complicated supplementation.

If you've only recently started training, you'll generally get far more benefit from improving your:

Training

Protein Intake

Calories

Creatine Intake

Sleep

Recovery

But the longer you've trained, the harder additional progress can become.

That's when advanced ingredients become more interesting.

For experienced athletes who already have the fundamentals covered, DL-185® provides a human-studied peptide-based ingredient that can be layered on top of an already well-designed nutrition and supplementation program.

Who Probably Doesn't Need DL-185®?

DL-185® isn't necessarily the first supplement we'd recommend to everyone.

If you aren't consistently resistance training, aren't consuming enough protein or haven't covered the basic performance-nutrition fundamentals yet, there are probably better places to start.

Build the foundation first.

Then optimise.

A sensible supplement hierarchy would generally begin with:

QUALITY PROTEIN

↓

CREATINE

↓

ADEQUATE CARBOHYDRATES & HYDRATION

↓

TRAINING-SPECIFIC SUPPLEMENTATION

↓

ADVANCED INGREDIENTS SUCH AS DL-185®

Is DL-185® Right for You?

DL-185® makes the most sense if you're:

✓ Resistance training consistently

✓ Focused on building muscle or strength

✓ Training with relatively high volume or frequency

✓ Looking to support muscular recovery and adaptation

✓ Already consuming adequate dietary protein

✓ Interested in emerging sports-nutrition ingredients backed by human research

✓ Looking for a stimulant-free supplement that can be used every day

If that sounds like your training, Ultra Labs DL-185® is designed for exactly that next level of sports nutrition.

One Simple Daily Serving

4 CAPSULES

2,000MG DILEUCINE

ONCE DAILY

No stimulants.

No cycling required.

No complicated protocol.

Just the 2g daily dileucine dose investigated in published human research.

FOR PEOPLE WHO DON'T JUST TRAIN - THEY PROGRESS.

How to Take DL-185® - Dosage, Timing & Training Days

One of the biggest advantages of Ultra Labs DL-185® Dileucine is its simplicity.

There's no complicated loading phase, stimulant timing or elaborate supplementation protocol.

Ultra Labs provides:

2,000MG DILEUCINE

4 CAPSULES

ONCE DAILY

And importantly, 2,000mg is the dose investigated in published human research.

What Is the Recommended DL-185® Dosage?

Take:

4 Capsules Daily

This provides a complete 2,000mg serving of dileucine (L-leucyl-L-leucine monohydrate).

There's currently no compelling reason to assume that taking more than the studied 2g daily amount will produce better results.

For most users, we'd stick with the full 4-capsule / 2,000mg daily serving.

When Should You Take DL-185®?

A common question is:

Should I take DL-185® before or after training?

At this stage, human research hasn't established one specific time of day as the definitive optimal timing strategy for dileucine.

That means we wouldn't tell you that DL-185® must be taken exactly 30 minutes before training or immediately after your final set.

Daily consistency is the priority.

A practical approach is to take your full serving at approximately the same time each day.

Can You Take DL-185® Pre-Workout?

Yes.

DL-185® can easily be incorporated into your pre-workout supplement routine.

However, don't expect it to feel like a traditional pre-workout.

DL-185® contains:

NO CAFFEINE

NO STIMULANTS

NO ACUTE ENERGY INGREDIENTS

Its purpose is to support the nutritional processes surrounding muscle protein synthesis, recovery and training adaptation, rather than provide an immediate stimulant effect.

Can You Take DL-185® Post-Workout?

Yes.

Taking DL-185® around your post-workout nutrition is another practical option.

Resistance training stimulates muscle protein turnover, while amino-acid availability plays an important role in the recovery and adaptation process.

Dileucine has been investigated for its effect on muscle protein synthesis, and newer research has also examined dileucine-containing essential amino-acid nutrition following resistance exercise.

This makes post-workout a logical and convenient time to take DL-185® — but current evidence doesn't establish that post-workout dosing is superior to taking your daily serving at another time.

Should You Take DL-185® on Rest Days?

Yes - if you're following the daily supplementation approach used in the longer-term human research.

The 10-week resistance-training study provided participants with 2g of dileucine every day, rather than only on training days.

This is also a useful reminder that recovery doesn't suddenly stop when you leave the gym.

Your body continues repairing, remodelling and adapting between training sessions.

A simple protocol therefore looks like:

TRAINING DAYS

4 capsules / 2,000mg daily

REST DAYS

4 capsules / 2,000mg daily

Simple.

Consistent.

Easy to follow.

Should You Take DL-185® With Protein?

DL-185® should not replace your dietary protein intake.

Dileucine provides a specialised leucine-containing dipeptide, whereas complete dietary proteins provide all of the essential amino acids required for muscle protein synthesis.

For athletes focused on muscle growth and recovery, the foundation should remain:

Adequate Daily Protein

• 
  

High-Quality Protein Sources

• 
  

Progressive Resistance Training

• 
  

Adequate Calories & Recovery

DL-185® can then be added alongside those fundamentals.

There's no need to choose between protein OR DL-185®.

They serve different nutritional roles.

Can You Take DL-185® With Creatine?

Yes.

DL-185® and creatine target different aspects of sports performance and therefore make a logical combination.

CREATINE

Supports rapid energy production, strength, high-intensity exercise capacity and increases in lean mass when combined with resistance training.

DL-185® DILEUCINE

Provides a human-studied leucine dipeptide investigated for muscle protein synthesis and resistance-training adaptations.

For most serious lifters, creatine remains one of the foundational supplements we'd recommend establishing first.

DL-185® can then be layered on top as a more advanced addition.

Can DL-185® Be Taken With Pre-Workout?

Yes.

Because DL-185® is stimulant-free, it can easily be used alongside your normal pre-workout.

For example:

PRE-WORKOUT + CREATINE + DL-185®

can all form part of the same supplementation program.

There's also no requirement to take DL-185® with caffeine for it to work.

Do You Need to Cycle DL-185®?

Current human research doesn't establish a requirement to cycle dileucine on and off.

The longer-term resistance-training study used 2g daily for 10 consecutive weeks.

Based on the available evidence, we'd prioritise consistent daily use rather than complicated cycling protocols.

The Simple DL-185® Protocol

If you don't want to overthink it:

TAKE 4 CAPSULES DAILY

↓

GET 2,000MG DILEUCINE

↓

TRAIN CONSISTENTLY

↓

CONSUME ENOUGH PROTEIN

↓

RECOVER

↓

REPEAT

The fundamentals still matter most.

DL-185® is there to help you optimise them.

2,000MG. ONCE DAILY. TRAINING DAYS & REST DAYS.

What Can You Stack With DL-185®?

Ultra Labs DL-185® doesn't need to be taken alone.

Because dileucine targets muscle protein metabolism and resistance-training adaptation rather than acting as a stimulant, DL-185® can easily sit alongside the foundational supplements already used by serious athletes.

The key is choosing supplements that complement DL-185® rather than simply duplicating its role.

Here are some of the combinations that make the most sense.

DL-185® + Creatine Monohydrate

Our First Choice for Strength & Performance

If your goal is strength, muscle and resistance-training performance, creatine is one of the first supplements we'd combine with DL-185®.

The two ingredients have very different roles.

DL-185® DILEUCINE

Supports muscle protein synthesis and has been investigated for resistance-training adaptations, including lower-body strength and muscular endurance.

CREATINE MONOHYDRATE

Supports rapid ATP regeneration, high-intensity exercise capacity, strength and lean-mass development when combined with resistance training.

This makes the combination particularly attractive for:

• Bodybuilders
• Powerlifters
• Strength athletes
• CrossFit athletes
• Hybrid athletes
• Anyone following a progressive resistance-training program

Think of it as attacking performance from two different directions:

CREATINE → Training Capacity & High-Intensity Performance

DL-185® → Muscle Protein Metabolism & Training Adaptation

If you're only starting to build your supplement program, we'd generally establish adequate protein and creatine first, then consider DL-185® as the more advanced addition.

DL-185® + Whey Protein

Build the Foundation First

DL-185® should never be viewed as a replacement for protein.

Dileucine provides a specialised leucine-containing dipeptide.

A complete protein source such as whey provides all nine essential amino acids required to construct new muscle proteins.

That makes the two fundamentally different.

WHEY PROTEIN

Provides the amino-acid building blocks needed to support muscle protein synthesis and help you reach your daily protein target.

DL-185®

Provides 2,000mg of the specialised dileucine peptide investigated in human muscle-protein-synthesis and resistance-training research.

For someone trying to maximise muscle development and recovery, the priority remains:

TRAIN HARD

• 
  

CONSUME ENOUGH TOTAL PROTEIN

• 
  

USE CREATINE

• 
  

RECOVER PROPERLY

Then add advanced ingredients such as DL-185® on top of that foundation.

DL-185® + Essential Amino Acids

An Interesting Post-Workout Combination

This combination is particularly interesting because newer human research has actually investigated dileucine as part of an essential-amino-acid formula following resistance exercise.

In that study, participants consumed a formula providing:

2g Dileucine

1g Additional Leucine

9.15g Total Essential Amino Acids

after a whole-body resistance-training session.

The dileucine + EAA treatment supported greater whole-body leucine retention than the collagen comparison, while muscle-protein-synthesis findings were promising but not definitively significant across all comparisons.

This doesn't prove that every DL-185® + EAA combination will produce the same result.

However, it provides an interesting scientific rationale for athletes who already use EAAs around training and want to incorporate dileucine into their recovery nutrition.

DL-185® + PeptiStrong®

Advanced Peptide-Based Sports Nutrition

For someone wanting to build a more advanced muscle and recovery stack, DL-185® + PeptiStrong® is an interesting combination.

These are two very different peptide-based ingredients.

DL-185® DILEUCINE

A leucine dipeptide investigated in human research for muscle protein synthesis, strength and muscular endurance.

PEPTISTRONG®

A bioactive peptide ingredient derived from fava bean protein hydrolysate and positioned around muscle health, strength and recovery.

Rather than simply doubling the dose of one ingredient, this approach combines two distinct peptide-based sports-nutrition technologies.

It's important to be clear:

DL-185® and PeptiStrong® have not, to our knowledge, been clinically studied together as a combination.

So we wouldn't claim that stacking them creates a clinically proven synergistic effect.

Instead, this is an advanced option for experienced athletes who want to combine two separately researched ingredients within a broader muscle-performance and recovery program.

DL-185® + LJ100® Tongkat Ali

Performance + Adaptation Stack

Another interesting Ultra Labs combination is DL-185® + LJ100® Tongkat Ali.

Again, these ingredients work very differently.

DL-185®

Targets the nutritional side of muscle protein metabolism and resistance-training adaptation.

LJ100®

Is a standardised Eurycoma longifolia extract with its own body of human research investigating areas including hormonal health, stress, wellbeing and exercise-related outcomes.

This makes the combination particularly appealing to experienced adult athletes looking for a broader performance-support stack.

However, DL-185® and LJ100® have not been clinically studied together, so we don't describe the combination as having proven synergy.

Think of them instead as two independently researched ingredients targeting different areas of performance nutrition.

The Ultimate DL-185® Muscle & Performance Stack

For an experienced resistance-trained athlete looking to build a comprehensive supplement program, we'd structure it like this:

FOUNDATION

HIGH-PROTEIN DIET

Provides the essential amino acids required for muscle repair and development.

PERFORMANCE

CREATINE MONOHYDRATE

Supports strength and high-intensity training capacity.

ADVANCED MUSCLE SUPPORT

ULTRA LABS DL-185®

Provides 2,000mg of human-studied dileucine.

OPTIONAL ADVANCED ADDITION

ULTRA LABS PEPTISTRONG®

Adds a second peptide-based ingredient with a different composition and research profile.

The result isn't a replacement for hard training.

It's a supplement strategy designed to support the work you're already doing.

What Would We Prioritise?

If you're wondering where DL-185® should fit into your supplement budget, we'd generally prioritise:

1. Adequate daily protein

↓

2. Creatine monohydrate

↓

3. Carbohydrates, hydration & electrolytes appropriate for your training

↓

4. DL-185® Dileucine

↓

5. Additional goal-specific supplements such as PeptiStrong® or LJ100®

That approach ensures you're not spending money on advanced supplementation while ignoring the fundamentals that produce the majority of your results.

Once those fundamentals are covered, DL-185® becomes an exciting evidence-based addition for athletes looking to take their resistance-training nutrition another step further.

BUILD THE FOUNDATION.

THEN OPTIMISE THE DETAILS.

Ultra Labs DL-185® Frequently Asked Questions

What is DL-185®?

DL-185® is a dileucine peptide, scientifically known as L-leucyl-L-leucine.

Dileucine consists of two leucine molecules bonded together to form a dipeptide.

It has attracted interest in sports nutrition because human research has investigated its effects on muscle protein synthesis, strength, muscular endurance and resistance-training adaptation.

Ultra Labs DL-185® provides 2,000mg of dileucine per 4-capsule daily serving.

Is DL-185® a peptide?

Yes.

Dileucine is a dipeptide, meaning it consists of two amino acids linked by a peptide bond.

In this case, those two amino acids are both leucine:

LEUCINE + LEUCINE → DILEUCINE

This is why DL-185® can legitimately be described as a peptide-based sports-nutrition ingredient.

It should not, however, be confused with injectable pharmaceutical peptides.

DL-185® is an orally consumed nutritional dipeptide.

What is L-Leucyl-L-Leucine?

L-leucyl-L-leucine is the scientific name for dileucine.

It consists of two L-leucine molecules joined together through a peptide bond.

You'll therefore see the terms:

DL-185®

Dileucine

L-Leucyl-L-Leucine

used throughout this page.

They refer to the leucine dipeptide at the centre of the DL-185® formula.

What does DL-185® do?

DL-185® provides dileucine, which has been investigated in human research for its effects on:

• Muscle protein synthesis
• Resistance-training adaptation
• Maximum strength
• Muscular endurance
• Post-exercise amino-acid metabolism

The strongest current evidence relates to muscle protein metabolism and specific resistance-training outcomes.

DL-185® should be used alongside - not instead of - adequate protein intake, progressive resistance training and proper recovery.

Does DL-185® help build muscle?

Potentially, but this needs to be explained accurately.

Human research has demonstrated that 2g of dileucine can significantly stimulate muscle protein synthesis, an important biological process involved in muscle repair and adaptation.

However, a 10-week resistance-training study did not demonstrate significantly greater gains in fat-free mass or muscle thickness with dileucine compared with the other groups.

So we don't describe DL-185® as clinically proven to directly build more muscle.

Instead, it is better viewed as a supplement designed to support the muscle protein synthesis and resistance-training adaptation processes that contribute to long-term muscular development.

Does DL-185® increase muscle protein synthesis?

Human research has demonstrated that 2,000mg of dileucine significantly increased cumulative muscle protein synthesis over a three-hour measurement period.

Interestingly, the same 2,000mg dose of free-form leucine did not significantly increase cumulative muscle protein synthesis under the same experimental conditions.

This doesn't mean leucine itself isn't important for muscle protein synthesis.

Rather, it suggests the dileucine peptide may behave differently from an equal dose of isolated free-form leucine.

Is DL-185® better than leucine?

For certain outcomes, human research comparing equal 2g doses has produced favourable findings for dileucine.

In an acute study, 2g dileucine significantly increased cumulative muscle protein synthesis, while 2g free-form leucine did not under the same experimental conditions.

In a longer 10-week resistance-training study, dileucine produced a greater improvement in leg-press repetitions-to-failure compared with leucine.

However, this doesn't establish that dileucine is superior to leucine in every situation or at every possible dose.

Leucine remains an essential amino acid with an important role in muscle protein metabolism.

How much DL-185® should I take?

Ultra Labs DL-185® provides:

4 CAPSULES = 2,000MG DILEUCINE

The 2g serving is particularly relevant because 2,000mg is the quantity investigated in published human dileucine research.

Follow the directions provided on the product label.

When should I take DL-185®?

Consistency is more important than trying to identify a theoretical perfect minute to take DL-185®.

In longer-term resistance-training research, participants consumed 2g of dileucine daily.

On training days in the 10-week study, supplementation was consumed within 60 minutes after training, while on non-training days it was consumed with the participants' first meal.

That doesn't prove post-workout dosing is superior to every other timing strategy, but it provides a useful research-based protocol for those wanting to follow the studied approach.

Should I take DL-185® on rest days?

If you're following the protocol used in the longer-term human research, yes.

Participants consumed 2g dileucine every day for 10 weeks, including non-training days.

Remember that muscular recovery and adaptation continue between training sessions.

Should DL-185® be taken pre-workout or post-workout?

DL-185® isn't a stimulant-based pre-workout, so you don't need to take it immediately before training to experience an energy effect.

The 10-week resistance-training study administered the supplement within 60 minutes post-workout on training days.

Post-workout is therefore a practical option based on the published study protocol.

However, current evidence doesn't establish that this timing is necessarily superior to every other way of taking your daily 2g serving.

Does DL-185® reduce DOMS?

Current published human dileucine research has not established that DL-185® significantly reduces delayed onset muscle soreness (DOMS).

Although DL-185® is relevant to muscle recovery because of its effects on muscle protein metabolism and training adaptation, we don't believe it's accurate to claim that dileucine has been clinically proven to reduce DOMS based on the currently available evidence.

Does DL-185® improve strength?

Human research provides some promising evidence.

During a 10-week resistance-training study, participants consuming 2g of dileucine daily demonstrated a significantly greater improvement in leg-press 1RM strength compared with placebo.

However, dileucine didn't significantly outperform every comparison group across every strength measurement.

The evidence is therefore best described as supporting specific resistance-training strength outcomes, rather than claiming DL-185® universally increases strength.

Does DL-185® improve muscular endurance?

The 10-week resistance-training study found that dileucine produced a significantly greater improvement in leg-press repetitions-to-failure compared with the group consuming the same 2g dose of free-form leucine.

This makes muscular endurance during resistance exercise one of the more interesting areas of the emerging dileucine research.

Is DL-185® a stimulant?

No.

DL-185® is completely different from a traditional stimulant-based pre-workout.

Dileucine is a peptide consisting of amino acids and doesn't provide caffeine or an acute stimulant energy effect.

This makes DL-185® suitable for use regardless of whether you train in the morning, afternoon or evening.

Can I take DL-185® with creatine?

DL-185® and creatine have different roles and can form part of the same broader sports-nutrition program.

Creatine has extensive evidence supporting strength, high-intensity exercise performance and lean-mass development when combined with resistance training.

Dileucine has emerging human evidence surrounding muscle protein synthesis and resistance-training adaptation.

However, the combination itself has not been established as producing a clinically proven synergistic effect.

Can I take DL-185® with protein?

Yes.

In fact, DL-185® should not replace your dietary protein.

Protein provides all of the essential amino acids required to construct new muscle proteins, while DL-185® provides the specialised dileucine peptide.

Think:

PROTEIN = FOUNDATION

DL-185® = ADVANCED ADDITION

Can I stack DL-185® with PeptiStrong®?

DL-185® and PeptiStrong® can be incorporated into the same broader sports-nutrition strategy because they are distinct peptide-based ingredients.

However, they have not been clinically studied together, so we don't claim that combining them creates a proven synergistic effect.

This is best viewed as an advanced stack for experienced athletes who already have their training, protein intake and foundational supplementation covered.

Do I need to cycle DL-185®?

Published longer-term research has investigated 2g of dileucine daily for 10 consecutive weeks.

Current evidence doesn't establish a specific requirement to cycle dileucine on and off.

Follow the product directions and seek appropriate professional advice if you have individual circumstances that may affect supplement use.

Who is DL-185® best for?

DL-185® is particularly suited to people performing regular resistance-based training, including:

• Bodybuilders
• Strength athletes
• Powerlifters
• CrossFit athletes
• Functional fitness athletes
• Hybrid athletes
• High-volume resistance trainers
• Experienced gym users

It's particularly interesting for people who already have the fundamentals covered and want to explore more advanced, human-studied sports-nutrition ingredients.

Is DL-185® suitable for beginners?

It can be used by people at different training levels, but it wouldn't generally be the first supplement we'd prioritise for a beginner.

For someone new to training, we'd focus first on:

Consistent Resistance Training

Adequate Protein

Appropriate Calories

Creatine Monohydrate

Sleep & Recovery

Once those fundamentals are established, advanced ingredients such as DL-185® become much more relevant.

How long does DL-185® take to work?

There isn't currently enough evidence to give everyone a specific timeframe in which they should expect to “feel” DL-185® working.

DL-185® isn't a stimulant, so you shouldn't expect an immediate caffeine-like sensation.

Acute research has measured changes in muscle protein metabolism during the hours following dileucine ingestion, while longer-term performance research supplemented participants daily for 10 weeks alongside resistance training.

It's therefore better viewed as a consistent training and recovery supplement rather than an instant-effect product.

Is Ultra Labs DL-185® the same dose used in human research?

Yes — the daily amount aligns with the dose used in the key published human studies.

Ultra Labs provides:

2,000MG DILEUCINE

per 4-capsule daily serving.

Published human research has investigated 2g of dileucine in both acute muscle-protein-synthesis research and longer-term resistance-training supplementation.

That's one of the most important features of the Ultra Labs formula:

A FULL 2,000MG HUMAN-STUDIED DAILY SERVING.

DL-185® Dileucine - Human Research & Scientific References

The interest surrounding DL-185® Dileucine isn't based purely on theory.

Dileucine - scientifically known as L-leucyl-L-leucine - has now been investigated in controlled human studies examining muscle protein synthesis, resistance-training adaptations and post-exercise amino-acid metabolism.

Most importantly, the 2,000mg daily serving of dileucine provided by Ultra Labs DL-185® aligns with the 2g dose used in key published human studies.

Here are the major studies behind the science.

Study 1: Dileucine vs Leucine & Muscle Protein Synthesis

Paulussen et al. – Journal of Applied Physiology, 2021

Study:
Dileucine ingestion is more effective than leucine in stimulating muscle protein turnover in young males: a double blind randomized controlled trial.

Study Design

Researchers recruited 10 healthy young males and used a randomized crossover design to compare:

2g Dileucine

vs.

2g Free-Form Leucine

Researchers used blood sampling, muscle biopsies and stable isotope techniques to investigate muscle protein synthesis and muscle protein breakdown.

Key Finding

Over the three-hour measurement period:

2g Dileucine significantly increased cumulative muscle protein synthesis.

The equivalent 2g dose of free-form leucine did not significantly increase cumulative muscle protein synthesis under the same experimental conditions.

Muscle protein breakdown did not significantly differ between the treatments.

Why It Matters

This study provided important human evidence that dileucine can influence muscle protein metabolism differently from an equivalent dose of isolated free-form leucine.

Published in: Journal of Applied Physiology
Volume: 131
Pages: 1111–1122
Year: 2021
PMID: 34323596
DOI: 10.1152/japplphysiol.00295.2021

Study 2: Dileucine During 10 Weeks of Resistance Training

Hagele et al. – PLOS ONE, 2024

Study:
Dileucine ingestion, but not leucine, increases lower body strength and performance following resistance training: A double-blind, randomized, placebo-controlled trial.

Study Design

Researchers recruited 34 resistance-trained males who completed a structured four-day-per-week resistance-training program for 10 weeks.

Participants consumed:

2g Dileucine Daily

vs.

2g Leucine Daily

vs.

Placebo

Researchers assessed numerous outcomes including strength, repetitions-to-failure, body composition, muscle thickness, anaerobic capacity and jump performance.

Key Findings

After 10 weeks:

✓ Dileucine produced a significantly greater improvement in leg-press 1RM compared with placebo.

✓ Dileucine produced a significantly greater improvement in leg-press repetitions-to-failure compared with leucine.

Not every performance or body-composition outcome differed significantly between groups.

In particular, the study did not establish that dileucine produced significantly greater muscle hypertrophy or fat-free-mass gains than the comparison groups.

Why It Matters

This takes the research beyond an acute muscle protein synthesis response.

It provides human evidence examining 2g of dileucine consumed daily during a real 10-week resistance-training program in already resistance-trained males.

Published in: PLOS ONE
Year: 2024
PMID: 39739679
DOI: 10.1371/journal.pone.0312997

Study 3: Dileucine + Essential Amino Acids After Resistance Exercise

Aguilera et al. – Journal of the International Society of Sports Nutrition, 2025

Study:
Dileucine-supplemented essential amino acids support whole-body anabolism after resistance exercise and serum-stimulated cell-based anabolism.

Study Design

12 healthy adults completed approximately 60 minutes of whole-body resistance exercise before consuming one of three nutritional treatments.

The dileucine-containing EAA formula provided:

2g Dileucine

1g Additional Leucine

9.15g Total Essential Amino Acids

Researchers compared this with a BCAA formula and an isonitrogenous collagen treatment.

Key Findings

The dileucine + EAA and BCAA treatments produced greater exogenous leucine retention than collagen, which the researchers used as an estimate of whole-body anabolism.

Stable-isotope-derived mixed muscle protein synthesis showed a trend toward an overall treatment effect, but this did not reach conventional statistical significance.

Important Context

This study did not investigate 2g of dileucine in isolation.

Dileucine was consumed as part of a complete essential-amino-acid formula.

The findings therefore cannot all be attributed specifically to dileucine.

However, the study adds another important piece to the growing human research examining dileucine within post-resistance-exercise nutrition.

Published in: Journal of the International Society of Sports Nutrition
Volume: 22
Year: 2025
Article: 2590090
PMID: 41321015
DOI: 10.1080/15502783.2025.2590090

What Does the Human Research Currently Support?

Taken together, published human research provides evidence that:

✓ 2g Dileucine can significantly stimulate muscle protein synthesis

✓ Dileucine can produce different physiological effects from an equal 2g dose of free-form leucine

✓ 2g daily has been studied during 10 weeks of structured resistance training

✓ Dileucine produced greater leg-press strength improvements than placebo in that trial

✓ Dileucine produced greater leg-press repetitions-to-failure improvements than leucine

✓ Dileucine has also been investigated as part of an EAA formula following resistance exercise

The evidence is promising - but still emerging.

Current research does not establish that dileucine:

✗ Produces greater muscle growth than adequate protein intake

✗ Improves every measure of athletic performance

✗ Has been clinically demonstrated to reduce DOMS

✗ Replaces the need for adequate dietary protein

That's why we prefer to position Ultra Labs DL-185® for what the evidence currently supports:

MUSCLE PROTEIN SYNTHESIS

RESISTANCE-TRAINING ADAPTATION

STRENGTH & MUSCULAR PERFORMANCE SUPPORT

Research-Driven Sports Nutrition

There's a big difference between an ingredient having an interesting mechanism on paper and actually being investigated in humans.

Dileucine now has controlled human research examining both acute muscle protein metabolism and longer-term resistance-training outcomes.

And Ultra Labs provides:

2,000MG DILEUCINE PER DAILY SERVING

matching the 2g quantity investigated in the key human studies.

HUMAN STUDIED.

RESEARCH DRIVEN.

2,000MG PER SERVE.

Learn More About DL-185® Dileucine

Want to go deeper into the science behind DL-185® Dileucine, leucine peptides and advanced sports nutrition?

Explore our DL-185® guides below for a more detailed look at how dileucine compares with traditional leucine and how it can be incorporated into a broader performance supplement stack.

DL-185® vs Leucine: Is Dileucine the Next Evolution in Muscle Recovery?

What's actually different about dileucine compared with ordinary free-form leucine?

In this guide, we break down DL-185® vs leucine, explain the structural difference between leucine and the L-leucyl-L-leucine dipeptide, and examine the human research comparing equal doses for muscle protein synthesis and resistance-training performance.

→ READ: DL-185® vs Leucine

LJ100® + DL-185®: The Ultimate Lean Muscle Performance Stack

Looking to build a more comprehensive performance stack?

Discover why athletes are combining DL-185® Dileucine with LJ100® Tongkat Ali and how these two independently researched ingredients target different aspects of performance nutrition.

We break down the science behind each ingredient, who the combination may be best suited for, and where it fits alongside your training, protein intake and foundational supplementation.

→ READ: LJ100® + DL-185® – The Ultimate Lean Muscle Performance Stack

The M&M Fitness DL-185® Research Hub

We're continually expanding our DL-185® educational content as new research becomes available.

Our goal is simple:

Cut through the marketing hype and explain what the human research actually shows.

Whether you're researching dileucine vs leucine, muscle protein synthesis, recovery, strength, muscular performance or peptide-based sports nutrition, you'll find our latest DL-185® guides right here.

LEARN THE SCIENCE.

UNDERSTAND THE INGREDIENT.

THEN DECIDE IF DL-185® IS RIGHT FOR YOUR TRAINING.

Buy Ultra Labs DL-185® Dileucine in Australia

Looking to buy Ultra Labs DL-185® Dileucine Peptide in Australia?

M&M Fitness Nutrition & Supplements stocks Ultra Labs DL-185® for athletes looking for an advanced, human-studied addition to their muscle recovery and performance nutrition.

Each full daily serving provides:

2,000MG DILEUCINE

4 CAPSULES PER SERVE

30 DAILY SERVINGS

STIMULANT FREE

Most importantly, the 2,000mg daily serving aligns with the 2g dose investigated in key published human dileucine research.

Why Choose Ultra Labs DL-185®?

DL-185® isn't another stimulant promising an instant energy hit.

It's a specialised L-leucyl-L-leucine dipeptide developed for athletes interested in the nutritional processes surrounding muscle protein synthesis, resistance-training adaptation and muscular performance.

Human research has investigated 2g of dileucine for:

✓ Muscle Protein Synthesis

✓ Resistance-Training Adaptation

✓ Lower-Body Strength

✓ Muscular Endurance

And unlike many products built around exciting ingredients but underdosed formulas, Ultra Labs provides the full 2,000mg daily amount used in key published human research.

Why Buy DL-185® From M&M Fitness?

At M&M Fitness, we don't just put products on a shelf.

We want you to understand what you're taking, why you're taking it and whether it actually makes sense for your goals.

That's why we've gone beyond the standard manufacturer description and created this complete DL-185® research guide.

When you buy from M&M Fitness, you also get:

Australian Supplement Retailer

Shop DL-185® from an established Australian sports-nutrition retailer with fast Australia-wide delivery.

Expert Supplement Advice

Not sure whether DL-185® makes sense for your training?

Our team can help you work out where it fits alongside your protein, creatine, recovery nutrition and existing supplement program.

Price Beat Guarantee

Found Ultra Labs DL-185® cheaper at another Australian supplement retailer?

Ask us about our Price Beat Guarantee.

Don't feel uncomfortable asking - we've got you!

Shop Online or Visit Us In-Store

Order Ultra Labs DL-185® online for delivery across Australia or visit M&M Fitness in-store for personalised supplement advice.

Is DL-185® Worth Adding to Your Supplement Stack?

If you're new to training, start with the fundamentals.

Train consistently.

Eat enough protein.

Use creatine.

Sleep and recover properly.

But if those foundations are already covered and you're looking for a more advanced sports-nutrition ingredient, DL-185® becomes considerably more interesting.

You're getting a specialised dileucine peptide with emerging human research investigating muscle protein synthesis and resistance-training performance, delivered at the same 2g daily amount used in key published studies.

No magic.

No ridiculous promises.

Just an interesting new piece of sports-nutrition science for people who take their training seriously.

Ultra Labs DL-185® - 2,000mg Dileucine

HUMAN-STUDIED DILEUCINE

2,000MG PER DAILY SERVING

MUSCLE PROTEIN SYNTHESIS & TRAINING ADAPTATION SUPPORT

STIMULANT FREE

AVAILABLE IN AUSTRALIA FROM M&M FITNESS

READY TO TAKE YOUR RECOVERY NUTRITION TO THE NEXT LEVEL?

→ BUY ULTRA LABS DL-185® NOW