Glycine500 4g Amino Acid Powder, Unflavored, 15 Calories Per Sachet. May be used in low protein diets in a variety of ways: Mixed in with protein substitute, added to modular feeds, incorporated into other permitted food or drink. For Use In The Dietary Management of Inborn Errors of Amino Acid Metabolism From Birth. To be determined by the clinician or dietitian and is dependent on the age, body weight and medical condition of the patient.