Glycerin: What It Is, What It Does, and Is It Safe?

Glycerin is in more than 15,000 cosmetic products (CIR, 2015), and it has been used in skin preparations for many years (Fluhr et al., 2008). Here is what it is, what it does for dry skin and what the safety reviews found.

What is glycerin?

Glycerin, also called glycerol, is a clear, syrupy liquid. On a label it is written "Glycerin," its INCI name (the standard name used on cosmetic ingredient lists) (CIR, 2015).

Glycerin occurs naturally in all animals and plants, bound up in fats and oils. It can come from plants or animals, or be made from other starting materials, and the natural and synthetic forms are the same compound (CIR, 2015).

Your skin makes some glycerol of its own, and that natural glycerol plays a role in skin hydration (how much water skin holds), elasticity and barrier repair (Fluhr et al., 2008).

What does glycerin do in a cream?

Glycerin is a humectant, an ingredient that draws water into the outer layer of skin. The CIR safety report lists it as a humectant, a skin protectant and a skin conditioning agent, among other uses (CIR, 2015).

A 2008 review in the British Journal of Dermatology found that glycerol improves the water content of the stratum corneum (the outermost layer of skin), supports skin barrier function (how well skin holds water in and keeps irritants out), improves skin's mechanical properties such as elasticity, and helps protect against irritating stimuli (Fluhr et al., 2008).

The same review notes that the boost in skin moisture from glycerol matters most when skin is dry from cold, dry weather, as in winter (Fluhr et al., 2008).

FDA rules for over-the-counter skin protectant products list glycerin as an active ingredient at 20 to 45 percent (21 CFR 347.10).

Is glycerin safe?

The Cosmetic Ingredient Review (CIR) is the expert panel that reviews the safety of cosmetic ingredients in the U.S. It concluded that glycerin is safe in cosmetics in the present practices of use and concentration (CIR, 2015).

The report counted glycerin in 15,654 cosmetic products, used at up to 78.5 percent in leave-on products (CIR, 2015).

In human tests, glycerin at 50 percent in water did not irritate 420 people with dermatitis, and a moisturizer with 65.9 percent glycerin did not cause sensitization (an allergic reaction that builds after repeat contact) (CIR, 2015).

How to spot glycerin on a label

Look for "Glycerin." You may also see the name glycerol in research. In the U.S., cosmetic ingredients must be listed in descending order of predominance, so the ingredient with the most is listed first (FDA Cosmetics Labeling Guide).

Glycerin is on the Corium 21 label, right after certified organic aloe vera and water. You can see every ingredient on our Corium 21 ingredient list.

Wondering how glycerin compares with another popular humectant? Read glycerin vs. hyaluronic acid.

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FAQ

Is glycerin good for dry skin?

Research shows glycerol improves the water content of the outer layer of skin and supports the skin barrier, and a 2008 review notes this matters most for skin dried out by cold, dry weather (Fluhr et al., 2008).

Is vegetable glycerin the same as glycerin?

Yes, chemically. Glycerin from plants, from animals and made synthetically is the same compound (CIR, 2015).

Is glycerin safe on sensitive skin?

The CIR panel found glycerin safe as used in cosmetics, and in human testing 50 percent glycerin did not irritate 420 people with dermatitis (CIR, 2015).