Researchers had healthy young men in their late 20s consume 0.08 grams of either hydrolyzed whey or intact whey protein per kilogram of body weight. They found that both supplements increased blood concentrations of the BCAA leucine and the delivery of leucine to muscle.

Muscle protein synthesis, which plays a key role in building and maintaining muscle, also increased to a similar degree with both supplements, but phenylalanine utilization for synthesis remained elevated for around 3 hours with hydrolyzed whey compared to about 1 hour with intact whey protein.