Ingredients

Glycerin

Glycerin — chemically, glycerol — is one of the most widely used ingredients in cosmetics worldwide. It functions as a humectant, draws and binds water in the upper layers of the stratum corneum, and has an exceptionally favourable tolerability profile.

At a glance

INCI name

Glycerin

Synonyms

Glycerol; 1,2,3-propanetriol

CAS number

56-81-5

Regulatory class

Cosmetic ingredient (Regulation (EC) No 1223/2009); also pharmacopoeial substance (European Pharmacopoeia monograph "Glycerol") and authorised food additive (E422)

Cosmetic function

Humectant; solvent; viscosity controlling; denaturant

What it is

Glycerin is a colourless, odourless, viscous, sweet-tasting trihydric alcohol. It is hygroscopic — strongly attracting and holding water — which is the basis of its humectant role in cosmetic formulations. It is also a solvent for a wide range of polar substances, which makes it useful as a vehicle for actives and as a co-solvent in finished products. Commercial cosmetic glycerin is typically produced by hydrolysis of triglycerides in vegetable oils or by synthesis from propylene; pharmacopoeial-grade material follows the specifications in the European Pharmacopoeia.

How it is used in parapharmacy products

Glycerin appears in nearly every product category sold in a parapharmacy: facial and body moisturisers, cleansers, masks, oral hygiene cosmetics (toothpastes, mouthwashes), hair conditioners, shaving products, hand creams and infant-care preparations. Typical concentrations range from low single-digit per cent in light leave-on products to substantially higher concentrations in occlusive ointments and intensive moisturisers. Its sensorial profile contributes a slight "drag" or stickiness at high concentrations, which formulators manage by blending it with other humectants and emollients.

Regulatory status

Glycerin is not subject to specific restrictions in the Annexes of Regulation (EC) No 1223/2009. As with any cosmetic ingredient, its use is subject to the general safety requirement and to inclusion in the safety assessment for the finished product. The European Pharmacopoeia includes a monograph for glycerol that sets specifications for material used in pharmaceutical preparations; cosmetic-grade material is typically produced to comparable specifications. Glycerol is also authorised as a food additive in the EU under Annex II of Regulation (EC) No 1333/2008 (food additives), with the E-number E422.

Evidence summary

Glycerin's role as a topical humectant is well-established. A substantial number of studies, including controlled clinical work, has documented increases in stratum-corneum hydration following the application of glycerin-containing finished products. Glycerin is one of the comparator humectants against which other agents are tested in cosmetic-science studies. Claims used in connection with glycerin in commercial communications must in any case comply with Commission Regulation (EU) No 655/2013 on common criteria for cosmetic claims.

Safety and known considerations

Topical glycerin has a very favourable safety profile. Allergic contact dermatitis to glycerin is rare. It is widely used in products for sensitive skin, infant skin and post-procedural skin. Ingested in the small quantities found in cosmetic oral-hygiene products (toothpastes, mouthwashes), glycerin is not a safety concern; food-grade material is widely consumed in foods and pharmaceuticals.

Last reviewed: May 2026.