Glycine (not to be confused with ‘glycol’, ‘glycerine’, glycerol’, etc) is the simplest naturally occurring amino acid, which is a constituent of most proteins [1]. Glycine is one of 20 amino acids used to make proteins in the human body. It is found in high protein foods such as meat, fish, dairy products and legumes.

Which skincare products contain glycine?

Glycine is a buffering agent [2] – meaning it will turn an acidic or alkaline solution neutral when added to it. It’s used in antacids, analgesics, antiperspirants, cosmetics and personal care products. In cosmetics and personal care products, glycine functions primarily as a hair and skin conditioning agent with antistatic properties, meaning it acts to reduce or eliminate the effects of static electricity. Products in which glycine may be found include:

• baby products
• bath products
• cleansing products
• eye makeup
• shaving foams and creams
• hair and skincare products.

What are the health risks of glycine?

Glycine seems to be safe for most people when taken by mouth or applied to the skin. Most people do not experience side effects, although there have been a few reports of nausea, vomiting, stomach upset, and drowsiness [3].

The Cosmetic Ingredient Review (CIR) Expert Panel, which was established in 1976 as an independent safety review program for cosmetic ingredients, concluded that glycine is safe as used in cosmetic and personal care products. Since glycine is normally found in the body, the panel focused their review only on dermal irritation and sensitisation data, which indicated that this ingredient is not a dermal irritant or sensitiser.

However, not enough is known about the safety of glycine to recommend its use during pregnancy or when breast-feeding [3].

How can I avoid glycine?

If you are concerned, check your product list for glycine (also known as aminoacetic acid, aminoethanoic acid, glycoll, 2-aminoacetic acid, aciport or glycoamin) or its derivative, sodium glycinate.

“If you can’t see glycine listed but would like that extra peace of mind, just download the SkinNinja app and scan the product’s barcode to get a full breakdown of its constituent ingredients, as well as recommendations for healthier alternatives.”