Glycine is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐CH2‐COOH. Glycine is one of the proteinogenic amino acids.

Glycine is an amino acid that your body uses to create proteins, which it needs for the growth and maintenance of tissue and for making important substances, such as hormones and enzymes. Glycine is also one of three amino acids that your body uses to make a compound called creatine.