Branched-chain amino acids are essential nutrients. They are proteins found in food. Your muscles "burn" these amino acids for energy.
The specific amino acids that make up the branched-chain amino acids are leucine, isoleucine, and valine. The term branched-chain simply refers to their chemical structure.
Always tell your doctor about any supplements you are taking, including natural ones and those bought without a prescription. That way, your doctor can check on any potential side effects or interactions with any medications.
The U.S. Food and Drug Administration (FDA) does regulate dietary supplements; however, it treats them like foods rather than medications. Unlike drug manufacturers, the makers of supplements don’t have to show their products are safe or effective before selling them on the market.