Glycine

Also known as glycin.

Last reviewed October 9, 2026 · Jump to references

What is Glycine?

In plain words

Glycine is a small amino acid, one of the building blocks of protein, that the body makes and gets from food. The body uses it to build proteins and other important substances, and it helps nerve cells send signals. Researchers study it for sleep quality and blood sugar control. Human studies of these supplement uses are limited, so benefits are not firmly established.

Technical definition

Glycine is a nonessential, proteinogenic amino acid with a hydrogen side chain, making it the smallest amino acid and the only achiral standard amino acid. It activates inhibitory glycine receptors and serves as a co-agonist at NMDA-type glutamate receptors, while also contributing to the synthesis of collagen, glutathione, heme, and creatine. Glycine is marketed as a dietary supplement in the United States; supplement availability does not imply FDA approval for treating disease.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.