WHAT IS L ALANINE? Alanine is an essential amino acid that can be produced in the body. Alanine is the second most abundant amino acid in muscle tissue after. Alanine plays a role in the glucose-alanine cycle, ultimately removing pyruvate & glutamate from muscle to the liver. Alanine can be obtained via the diet. Rich sources include beef & fish. BULK POWDERS™ L Alanine is comprised of 100% L Alanine powder. A quick check of the Certificate of Analysis (COA) on this product page