Definition

A naturally-occurring derivative of glycine and a metabolic precursor of creatine. Glycocyamine, also known as guanidinoacetic acid (GAA), is catalyzed by guanidinoacetate N-methyltransferase to form creatine. Creatine, in phosphate form, helps supply energy to muscle cells for contraction. After intense effort, when adenosine triphosphate (ATP) deposits are depleted, creatine phosphate donates phosphate groups toward the fast synthesis of ATP. Dietary supplementation with GAA may improve muscle wasting associated with cancer and other chronic diseases.