Dec 29, 2016 So... I am wondering if someone can give me the break down. I'm under the impression that l-leucine is the most cruicial amino acid for a variety of things and especially muscle building. I also heard that it supposedly encourages/increases protein synthesis under different situations. Also heard it stimulates fat loss. Are there any medical journals or papers and truths in these matters? I get bulk raw l-leucine, but am i wasting my money? Yes I eat whole food already but hell if it's something relatively cheap anyway I can add it in for the benefit, otherwise if not meh? And with BCAAs, they already come with a few different things, i also get it raw bulk (tastes like vomit -- but mix in good protein shake and crap taste gone).