What is it?
The monoester of glycerin and oleic acid, a common unsaturated fatty acid. It is an emollient and emulsifier that softens skin and helps oil and water blend, and it appears in both rinse-off and leave-on products, including hair and eye-area products. Monoglycerides like it are widely used food emulsifiers, and glyceryl oleate is also used in medicines as an emulsifier and to help drugs be absorbed.
Key information
- The CIR Expert Panel found glyceryl oleate safe as used in 1986 and again in its amended review of monoglyceryl monoesters, published in 2020.
- In 2015 it was reported in 663 cosmetic products, at up to 3 percent.
- At 50 percent it caused no irritation or allergic sensitization in a repeat patch test completed by 93 volunteers.
- Mono- and diglycerides of fatty acids are food emulsifiers (E 471), which EFSA found to be of no safety concern in 2017.
More information
Glyceryl oleate is made by esterifying glycerin with oleic acid, by partly breaking down fats and oils, or by reacting fats and oils with glycerin. The result is a mixture that also contains some di- and triglycerides. No ethylene oxide is used, so it is not one of the PEG or ethoxylated emulsifiers.
The Cosmetic Ingredient Review (CIR) Expert Panel concluded in 1986 that glyceryl oleate is safe as used and reached the same conclusion in its amended review of the monoglyceryl monoesters, published in 2020. It was then reported in 663 products, at up to 3 percent. Preparations with 15 and 30 percent did not irritate human skin in single patch tests, and 50 percent in paraffin oil caused no irritation or allergic sensitization in a repeat patch test completed by 93 volunteers. In rabbits, undiluted glyceryl oleate was minimally irritating, although 20 days of daily application of a formulation containing it was severely irritating. The panel noted that monoglycerides can help other ingredients pass into the skin, a point for formulators.
Glyceryl oleate belongs to the mono- and diglycerides of fatty acids, which are permitted in EU foods as E 471. In its 2017 re-evaluation, which considered studies on monoglycerides rich in unsaturated fatty acids, the European Food Safety Authority (EFSA) expected them to be broken down in the gut into glycerol and fatty acids, reported neither cancer-causing potential nor a tumor-promoting effect, and found no safety concern at reported uses. Older feeding studies in one mouse strain had reported a few tumors; the CIR panel called those results equivocal.
Sources: Cosmetic Ingredient Review: Safety assessment of monoglyceryl monoesters as used in cosmetics (draft final amended report, 2015); Cosmetic Ingredient Review: Quick reference table of safety conclusions (September 2022); EFSA Journal (2017): Re-evaluation of mono- and di-glycerides of fatty acids (E 471) as food additives
