Ingredient dictionary

Glycine

Glycine is the simplest amino acid, a small protein building block that helps balance pH and condition skin and hair. It is on the label of 35 products in our library. Checked against our library November 6, 2026.

The catch: none for most people; check the full product list if your skin reacts easily.

What Glycine does

Adjusts and steadies product pH
Helps skin hold moisture
Conditions hair and skin

Glycine is one of the 20 common amino acids that make up proteins. It is the smallest of them, with just one hydrogen atom as its side chain. Cosmetic glycine is usually made in a lab, by chemical synthesis or fermentation. Your skin also contains amino acids like it, which are part of the natural moisturizing factor that keeps the outer layer supple.

Formulators use glycine mainly to adjust and steady pH, so the other ingredients stay stable. It also works as a mild humectant, which means it can help the skin hold on to water. You will often find it in deodorants, lotions, shampoos, and conditioners. It adds no scent and does not feel heavy or greasy on skin.

Good for

Suits most skin and hair types, since it is generally well tolerated and common in everyday products.

Be careful if

Nothing in particular for most skin types.

Frequently asked questions

Is glycine the same as glycerin?

No. Glycerin is a separate humectant, a simple alcohol that pulls water into the skin. Glycine is an amino acid that helps adjust pH and add mild moisture. They can appear in the same product and do different jobs.

Does glycine irritate sensitive skin?

Glycine is generally well tolerated and is a common, low-profile ingredient. No ingredient suits every skin type, though. If your skin reacts to a new product, stop using it and check with a dermatologist.