Free-Form, Pharmaceutical Grade Helps Build Lean Tissue L-Leucine is one of the three Branched Chain Amino Acids (BCAAs) that is critical in muscle tissue structure. Among the BCAAs, Leucine is unique in its role as a signaling molecule that helps to regulate optimal skeletal muscle protein synthesis in normal tissues. In addition, it helps to maintain already healthy glucose metabolism and insulin function, and may help to promote the use of fat for energy. Studies suggest that L-Leucine, in conjunction with adequate dietary protein, may help to build and maintain lean tissue and optimize body composition. NOW Leucine Powder is instantized for easy mixing in water, beverages or smoothies. No clumping.