L-Threonine F G 98.5% is an essential amino acid and cannot be synthesized by the human body, hence taken through nutrition by consumption from proteins in the food, meat, dairy, eggs, and some plant-based sources such as soy and beans for protein and other important molecule production. Being a vital amino acid taking part in many biological processes, L-Threonine is most likely to be a useful supplement in a balanced diet, though it must be taken with care not to consume its excess amounts. L-Threonine F G 98.5% is a premium grade of food-grade amino acid playing multiple important functions in the human body, ranging from the support of protein synthesis to stimulating the health of skin and digestive function.