Benefits
Superior muscle protein synthesis vs. leucine
DL-185® delivers 86% more leucine to muscle tissue within 30 minutes compared to the same dose of free-form leucine, translating to a 60% increase in mean myofibrillar fractional synthetic rate. This outperformance stems from absorption via the PEPT1 dipeptide transporter — an active transport mechanism not subject to the saturation ceiling of free amino acid absorption.
Greater strength gains in clinical RCT
In a 10-week randomized, double-blind, placebo-controlled trial in 34 resistance-trained males, DL-185® produced significantly greater leg press 1RM strength improvements vs. placebo (p=0.02) and outperformed an equivalent leucine dose. Participants following a 4-day/week resistance training program showed meaningful muscle performance advantages with 2g/day dileucine.
Anti-catabolic muscle preservation
DL-185® demonstrates anti-catabolic properties beyond its anabolic MPS stimulation — reducing muscle protein breakdown markers in preclinical studies. This dual anabolic/anti-catabolic profile makes it particularly valuable for cutting phases, aging athletes with anabolic resistance, or periods of caloric restriction where muscle preservation is critical.
Sarcopenia and aging muscle support
Aging muscle is characterized by anabolic resistance — a blunted MPS response to leucine that drives age-related muscle loss. DL-185® bypasses the absorption bottleneck that limits leucine effectiveness in aging muscle, making it one of the few ingredients with a mechanistic rationale for addressing sarcopenia at the amino acid delivery level.
Mechanism of action
PEPT1 dipeptide transporter absorption
Free leucine relies on LAT2 amino acid transporters that become saturated at high concentrations, limiting muscle delivery. DL-185® is absorbed via PEPT1 (peptide transporter 1) — a high-capacity active transporter in the intestinal brush border that handles dipeptides and tripeptides. This separate transport pathway achieves faster, more complete leucine delivery to systemic circulation and muscle tissue.
mTORC1 pathway activation
Once delivered intramuscularly, dileucine activates the mTORC1 (mechanistic Target of Rapamycin Complex 1) signaling cascade more effectively than free leucine — driving phosphorylation of p70S6K and 4E-BP1, the downstream effectors of muscle protein synthesis. The superior intramuscular leucine delivery achieved by DL-185® produces a stronger and more sustained mTORC1 activation signal.
Clinical trials
Randomized, double-blind, placebo-controlled trial in 34 resistance-trained males comparing 2 g dileucine (DL-185®) vs 2 g leucine vs placebo with resistance training. Outcomes: leg press 1RM, muscle protein synthesis, body composition. (2024)
34 resistance-trained males.
Dileucine group showed significantly greater leg press 1RM improvement vs placebo (p=0.02). Outperformed leucine group on some measures. Mechanism: dileucine (a leucine dipeptide) may have superior absorption kinetics and mTOR signaling efficiency vs free leucine. Note: small single trial; needs independent replication. Industry-funded.