DL185™ (L-Leucyl-L-Leucine Monohydrate) is quickly becoming one of the most talked-about innovations in modern muscle nutrition. This unique dipeptide, made from two bonded leucine molecules, has gained attention for how efficiently it’s absorbed, how rapidly it reaches the bloodstream, and the exciting research around its role in performance-focused formulations.
While regular leucine has long been associated with the signalling pathways that kickstart muscle protein synthesis (MPS), DL185™ takes this a step further by delivering leucine in a form the body handles differently from standard amino acids.
What Is DL185™?
DL185™ is a patented version of L-Leucyl-L-Leucine Monohydrate, a dipeptide created when two leucine molecules are enzymatically bonded together. While leucine itself is one of the most recognised amino acids for supporting the MPS signalling process, research shows that dileucine, the form found in DL185™, is handled differently during digestion and absorption.
Dileucine isn’t new to the human diet. It naturally exists in protein foods, especially animal proteins. But getting enough of it from food alone is extremely difficult, even with a high-protein intake. Research comparing food sources to DL185™ found that you would need to consume:
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159 g of whey protein concentrate (around eight 20 g servings)
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219 g of pea protein (around eleven 20 g servings)
to match the amount of dileucine found in just 12 g of DL185™.
Bottom Line: DL185™ delivers concentrated dileucine in amounts very difficult to achieve through normal dietary protein intake.
Why DL185™ Absorbs Differently: The PEPT1 Advantage
One of the most fascinating things about DL185™ is how it’s absorbed. Instead of relying solely on the standard amino acid transporters, DL185™ can utilise PEPT1, a specialised dipeptide transporter found in the small intestine. PEPT1’s job is to absorb dipeptides and tripeptides rapidly and efficiently, often faster than free-form amino acids.
Research suggests:
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DL185™ can take advantage of this PEPT1 pathway, potentially improving absorption speed.
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Some of the ingested DL185™ survives digestive breakdown and is absorbed intact as dileucine.
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Even supplementing with regular leucine increases blood dileucine slightly, suggesting the body naturally values and produces this form.
Bottom Line: DL185™ may use a unique and efficient pathway to deliver leucine equivalents more quickly than standard leucine alone.
Why Speed Matters for Muscle Protein Synthesis
For muscle protein synthesis to be activated effectively, the body needs to hit a specific leucine threshold—and reach it fast. While typical recommendations fall between 1.7–3.5 g of leucine, how quickly leucine peaks in muscle tissue matters just as much as the total amount consumed.
Studies comparing DL185™ to standard leucine found:
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2 g of DL185™ delivered 86% more leucine to muscle tissue within 30 minutes
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This fast delivery was associated with a higher fractional synthetic rate (FSR) compared to leucine alone
These results highlight why the dipeptide structure may offer advantages around training windows, where speed and efficiency of amino acid availability matter most.
Bottom Line: DL185™ allows faster delivery of leucine equivalents, helping support the rapid availability needed during key training periods.
Research on Strength, Endurance & Training Outcomes
When DL185™ was tested in multi-week training studies, several interesting observations emerged:
Strength Improvements
Participants supplementing with DL185™ demonstrated greater increases in strength measures compared to a control group. Standard leucine did not show the same degree of change.
Bottom Line: DL185™ may offer additional support during strength-focused programs.
Muscular Endurance & Training Volume
When directly compared to leucine, DL185™ showed statistically significant improvements in:
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Workout endurance
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Total repetitions
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Overall training volume
Bottom Line: DL185™ may help support improved endurance and work capacity during training.
These findings relate to controlled research conditions and are not therapeutic claims.
Where DL185™ Fits in Performance Formulations
Because of its concentrated leucine delivery, fast uptake, and research-backed absorption advantages, DL185™ is increasingly used in:
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Muscle-building formulas
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Strength & endurance blends
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Pre-workout products
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Post-workout and recovery formulations
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Healthy ageing and longevity blends
It’s a versatile ingredient wherever rapid amino acid availability is desirable.
How to Use DL185™ (General Guidance)
Research protocols commonly use:
➡ 2 g of DL185™, taken 30–45 minutes before training
It can be taken alone, or stacked with other well-established performance ingredients such as:
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Whey protein
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Creatine monohydrate
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Betaine
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Beta-alanine
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HMB
Always follow the usage instructions on the product label and speak with a qualified professional if you’re unsure.
Shop Ultra Labs DL185
At Nutrition Capital, we’re proud to offer DL185™ as part of our ingredient-driven supplement range.
As an independently owned retailer based in Victoria, we focus on trusted, transparent sourcing and fast dispatch, so you get premium-grade performance nutrition without delay.