Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women
How much of the EAA leucine in needed to maximize protein anabolism?
Researchers asked the same question and carried out a study to "determine the effects of different leucine concentrations in an isonitrogenous EAA mixture on muscle protein turnover (synthesis and breakdown) and associated cellular signaling."
They even "hypothesized that a concentration of leucine higher than that contained in a typical high-quality protein (~1.8g) would elicit an increase in MPS and mTORC1 signaling and decrease MPB and UPS and/or autophagy-lysosomal signaling in young adults."
Despite their hypothesis, they found that increasing the leucine concentration in 10g of EAAs from 1.8g to 3.5g did not "translate into significant improvements in MPS or overall muscle protein net balance."
This study demonstrated that ~1.8g of leucine per 10g of EAAs is sufficient to elicit a maximal protein anabolic response.
FYI, one serving of OptimalAmino contains 1.964g of leucine per serving (10g of EAAs).
Read the full-text here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2955876/
Glynn EL, Fry CS, Drummond MJ, Timmerman KL, Dhanani S, Volpi E, Rasmussen BB. Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women. J Nutr. 2010 Nov;140(11):1970-6. doi: 10.3945/jn.110.127647. Epub 2010 Sep 15. PMID: 20844186; PMCID: PMC2955876.