BCAA supplements come in the form of tablets or powder. BCAA or branch chain amino acids are the building blocks of proteins. Some amino acids are made by your body naturally, but others must be attained through diet. This supplement is popular among athletes and weight lifters. The powder form can be mixed with water in a supplement shaker and should ingested while working out, or immediately after. Amino acids will can speed up muscle recovery, curb appetite, increase metabolism, and decrease breakdown of lean muscle mass.