Amino acid
Isoleucine
Isoleucine is an essential amino acid, one of the three branched-chain amino acids (BCAAs), and has to come from food.
Also listed as L-Isoleucine
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
Every rating with its studiesGrouped by health goal, with the publications behind each rating
Why people take it
Fitness21.3%
Energy20.9%
Essential Health20.9%
Immune Support10.8%
Weight Management5.5%
Cognition4.7%
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Lysine
Valine
Leucine