What Is It?
Glycerin (sometimes called glycerol) is a naturally occurring alcohol compound found in all animal, plant, and human tissues, including the skin and blood. Glycerin used in cosmetics and personal care products can be obtained from natural sources (e.g., soybeans, cane, or corn syrup sugar) or manufactured synthetically. This synthetic form is chemically identical to naturally-occurring glycerin and the body handles both the same way.
Why is it used in cosmetics and personal care products?
Glycerin is used safely in numerous cosmetics and personal care products such as soaps, toothpaste, shaving cream, and skin/hair care products to provide smoothness and lubrication. It is also a well-known humectant that prevents the loss of moisture from products so they don’t dry out as quickly. Other reported functions for glycerin include use as a fragrance ingredient, denaturant, hair conditioning agent, oral care agent, skin conditioning agent— humectant, skin protectant, oral health care drug, and viscosity decreasing agent.
According to 2019 data in U.S. FDA’s Voluntary Cosmetic Registration Program (VCRP), glycerin is the third most frequently used ingredient in cosmetics (after water and fragrance). It was reported to be used in 23,366 products. This includes products for use near the eye, lipsticks, hair dyes and colors, bath soaps and detergents, skin care products, suntan preparations, and baby products.
According to a survey conducted by the Personal Care Products Council (PCPC) in 2014, glycerin was used at concentrations up to 99.4% in some skin cleaning products.
Glycerin is a precursor for synthesis of triglycerides and phospholipids in the liver and fat tissues. When the body uses stored fat as a source of energy, glycerol and fatty acids are released into the bloodstream.
Glycerin is widely used in the food industry and in pharmaceutical (i.e., drug) formulations. In food and beverages, glycerin serves as a humectant, a solvent, and a sweetener and may help with preservation. Most dried fruits, for instance, have glycerin added during processing to attract moisture so they don’t become brittle over time. Glycerin’s high sugar content makes it ideal as a sweetener in candies and cookies, and its ability to maintain a smooth texture is the reason why it is added to ice cream and used as the base of toothpaste. Healthcare providers sometimes give glycerol intravenously (by IV) to reduce pressure inside the brain in various conditions including stroke, meningitis, encephalitis, and central nervous system (CNS) trauma.
Scientific data supporting the safety of glycerin as used in cosmetics and personal care products was thoroughly reviewed in 2014 by the Cosmetic Ingredient Review (CIR) Expert Panel. Based on the available literature and data, the Expert Panel concluded glycerin is safe in the present practices of use and concentration (i.e., up to 79% in leave-on products, 99% in rinse-off products).
The U.S. Food and Drug Administration (FDA) recognizes glycerin as generally recognized as safe (GRAS) for its use in food packaging and it is a multiple-purpose GRAS food substance when used in accordance with good manufacturing practices. [21CFR182.9021CFR182.1320] Glycerin is on FDA’s list of approved direct and indirect food additives. [21CFR172.866, 21CFR175.300, 21CFR178.3500] Also, glycerin is FDA-approved for use in over-the-counter (OTC) drugs such as anorectal drug products, skin protectants, ophthalmic drugs, and oral health care products. [21CFR346.1421CFR347.1021CFR349.12]
European Union (EU)
Glycerin is listed on the EU’s Inventory of Cosmetic Ingredients (CosIng) and is not restricted in any way, according to the general provisions of the Cosmetics Regulation of the European Union. Glycerin derived from raw materials of animal origin must comply with European Union animal by-products regulations.
According to Canada’s List of Ingredients that are Restricted for Use in Cosmetics, product manufacturers of oral and leave-on products containing glycerin must ensure the raw material used is within the specifications of an accepted pharmacopoeia with respect to diethylene glycol (DEG) impurities (e.g. Glycerin Official Monograph in the most current edition of the USP).
More safety Information:
The available scientific data for glycerin demonstrated low oral and dermal (skin) adverse effects following single and repeated doses. In addition, data showed there were no reported allergic skin reactions in human clinical studies.
In multiple laboratory reproduction and developmental safety studies, glycerin did not produce any adverse effects on parental reproductive capability or growth development, fertility, or reproductive performance of their offspring. In a human fertility study of male employees who manufacture synthetic glycerin and who would be expected to be exposed to higher levels of the material than consumers using cosmetics, there were no differences observed in sperm counts or percentage of normally shaped sperm compared with a group who did not work with glycerin.
In addition, multiple laboratory studies showed glycerin did not cause genetic mutations nor was there evidence of increased tumor incidence where both natural and synthetic glycerin were administered orally for up to two years (i.e., glycerin does not cause cancer).