Labrada Nutrition's GlutaLean contains only pure pharmaceutical grade L-glutamine. Glutamine is an amino acid that accounts for about 60% of all free amino acids in the body. Muscle tissue contains especially high concentrations of glutamine. Insufficient glutamine in the diet has been associated with muscle tissue breakdown. Supplemental glutamine can help avoid muscle tissue breakdown, increase protein synthesis, increase glycogen storage (energy stores) in muscle, and can support healthy immune function.