Research
Mixed
Supplementation with glutamine or arginine does not enhance muscle protein synthesis or hypertrophy in healthy, well-nourished individuals performing resistance or endurance exercise.
Do not waste money on glutamine or arginine supplements for muscle building. They have been shown to have no effect on muscle protein synthesis or strength gains in healthy people.
StrongRefutesHIGH confidence
Neither arginine nor glutamine have been demonstrated to be effective at promoting resistance exercise-induced anabolism in humans and their inclusion in supplements has, on the basis of current evidence, no grounds.
Why this rating
Based on multiple controlled studies showing no effect.
Source
A Brief Review of Critical Processes in Exercise-Induced Muscular Hypertrophy
Stuart M. Phillips · Sports Medicine · 2014
narrative_reviewCited 266×
Read the paper This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →