Glycerin in Cosmetics: Any Adverse Effects?

Present in many types of care, the glycerin is particularly used as a humectant to soften and hydrate the skin, and reduce feelings of discomfort and flaking. So far, no major problems related to its skin use have been reported. Glycerin appears to be recognized as safe, non-toxic, non-irritating, non-sensitizing, and harmless as a cosmetic ingredient.

All skin types can use it daily, although it is more relevant for dry and dehydrated skin. Pregnant and breastfeeding women, as well as children, can safely use glycerol. However, caution is necessary, as there is not enough reliable information available. Always seek advice from your doctor.

Even though it may be rare, redness, itching, irritation, skin dryness, and a sensation of heat can occur. If any of these effects manifest, immediately stop using the product. If the rash does not disappear, be sure to consult your doctor. Although there don't seem to be many reported side effects, glycerin is a natural product and the risk of an allergic reaction is not exempt.

• Case No. 1 : The first allergic reactions to glycerin were reported over thirty years ago. Three cases of contact dermatitis out of several thousand patients suffering from eczema were reported after testing a glycerol-based product. In one of these cases, the apparent cause of the reaction was a mixture of 50% glycerin and 70% ethanol, applied to the hands after washing with water and soap. In the other two cases, a generalized dermatitis was triggered following the application of a moisturizing cream containing 10% glycerin.

• Case No. 2 : A study reported the case ofa 29-year-old woman who presented with a 7-month history of patchy eczema on her eyelids, face, neck, scalp, and underarms. The skin reaction occurred following the continuous use of glycerin (50%) in a hand moisturizer formulation. In this case, glycerin demonstrated its potential to act as a contact allergen. Her contact dermatitis disappeared when she avoided cosmetic products containing glycerin.

• Case No. 3 : A 2016 study reported that an 81-year-old patient developed a diffuse erythematous rash, which appeared acutely and generalized after a glycerin enema (50°C). Urticarial eruptions appeared 30 minutes after the enema and disappeared within an hour. Glycerin can also cause anaphylaxis. Indeed, the skin reactions were accompanied by an increase in body temperature (≈ 38°C) with stable vital signs.

Note : When ingested, glycerin can cause mild headaches, dizziness, nausea, vomiting, excessive thirst, and diarrhea in some individuals. That's why it is recommended to seek a doctor's advice before using glycerin orally.

Although glycerin is a natural compound beneficial for skin health and is considered safe for most people, it is important that certain precautions are taken.

• Before exposing your skin directly to a product containing glycerin for the first time, perform a patch test by applying a small amount of the product to a small area and waiting to see if the skin reacts;

• Consider the use of products containing glycerin as an ingredient rather than pure glycerin, as it can dehydrate and irritate the skin, as well as cause blister formation when dehydration is severe. As a humectant, glycerin draws water from the nearest source;

• Do not apply a glycerin-based product to a skin wound, infection, or cut without first consulting your doctor;

• Avoid using glycerin as a vaginal lubricant, despite its syrupy consistency seeming suitable. This can increase the risk of developing fungal infections.

• FORSTRUM L. & al. Contact hypersensitivity to glycerol. Contact Dermatitis (1976).

• HANNUKSELA M. Allergic and toxic reactions caused by cream bases in dermatological patients. International Journal of Cosmetic Science (1979).

• FINCH T. & al. Allergic contact dermatitis from glycerin in a moisturizing cream. Contact Dermatitis (2003).

• NAMIKI T. & al. Contact urticaria syndrome and protein contact dermatitis caused by glycerin enema. JAAD Case Reports (2016).

• HELDRETH B. & al. Safety assessment of glycerin as used in cosmetics. International Journal of Toxicology (2019).