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Medically reviewed by Last updated on Mar 27, 2023.

Excipient (pharmacologically inactive substance)

What is it?

Glycerin (C3H8O3), also known as glycerol and glycerine, is an odorless, colorless, oily, viscous liquid that has a sweet taste.

Synthetic glycerin is used in food products, nutritional supplements, pharmaceutical products, personal-care products, and oral-care products. In the pharmaceutical industry, glycerin is used as a sweetener in syrups, lozenges, and as an excipient in eyewash solutions. It my also be found in eardrop products, jellies and creams for topical use, in expectorants for congestion, suppositories, and gel capsules.

As an individual prescription product, glycerin has uses as a hyperosmotic, osmotic diuretic, and ophthalmic agent. It may be used as eye drop in the treatment of glaucoma to reduce intraocular pressure, as a solution or suppository for short-term treatment of constipation, to evacuate the bowel prior to colonoscopy, and in some ocular surgeries. It may be given intravenously to reduce pressure inside the brain, and used externally on the skin as a moisturizer. Glycerin has many other uses in the agricultural, food and pharmaceutical industry.

The U.S. Food and Drug Administration (FDA) classify glycerin as “generally recognized as safe” (GRAS). The overall risk of toxicity from glycerin found in pharmaceutical products is low. If one were to come into contact with large, bulk quantities of glycerin, eye irritation may occur. Skin irritation is unlikely unless the skin is damaged where contact occurs. Inhalational toxicity is low due to low volatility, but prolonged, excessive ingestion can cause elevated blood sugar or fat levels in the blood.[1][2][3]

List of medications using Glycerin


  1. [1]Dow Chemical. Glycerine. Product Safety Assessment. Accessed April 14, 2012.
  2. [2]FDA’s SCOGS database; glycerin and glycerides; SCOGS-Report Number: 30; Accessed April 14, 2012.
  3. [3] Glycerol. Accessed April 14, 2012.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.