Healthvit Glycine Amino Acid 500MG | 60 Capsules The principal function of glycine is that is an important building block of proteins. It is an essential amino acids. you use glycine every day to strengthen your body and, frankly, allow it to work properly. This amino acid is essential for many different muscle, cognitive and metabolic functions. It helps break down and transport nutrients like glycogen and fat to be used by cells for energy, and in the process, it supports strong immune, digestive and nervous systems. Glycine is the second most widespread amino acid found in human enzymes and proteins, which is why it has roles in nearly every part of the body. … It’s one of 20 amino acids used to make protein in the body, which builds the tissue that forms organs, joints and muscles.