What is it?
A conditioning ingredient made from the fatty acids of meadowfoam seed oil, from the plant Limnanthes alba. An estolide forms when fatty acids link to one another instead of to glycerin, as they do in ordinary oils. This one consists mainly of two of meadowfoam’s 20-carbon fatty acids joined into a single molecule. It is used in hair and skin care products as a conditioning agent.
Key information
- Meadowfoam estolide is made by linking the fatty acids of meadowfoam seed oil to one another, mainly in pairs.
- USDA researchers who developed meadowfoam estolides found them useful as hair conditioners.
- Neither the CIR Expert Panel nor the EU's SCCS has published a safety assessment of this ingredient, and the EU places no restrictions on it.
- The CIR Expert Panel found meadowfoam seed oil, its starting material, safe as used, including at up to 74 percent in leave-on products.
More information
Meadowfoam is a seed crop developed in the Pacific Northwest of the United States. Its oil is unusual: in the data the CIR reviewed, 52 to 77 percent of its fatty acids were eicosenoic acid, a 20-carbon monounsaturated fatty acid, with smaller amounts of erucic and docosadienoic acids. To make estolides, researchers split vegetable oil into its fatty acids and glycerin and then link the fatty acids together with the help of an acid catalyst. USDA researchers reported that meadowfoam estolide was useful as a hair conditioner but dark in color, which limited its use in cosmetics, and that distilling off the nearly colorless monoestolide, the two-fatty-acid form, gave a material suitable for cosmetics.
Meadowfoam estolide has not been reviewed on its own by the Cosmetic Ingredient Review (CIR) Expert Panel, and the EU cosmetic ingredient database lists no opinion from the EU’s Scientific Committee on Consumer Safety (SCCS) and no restrictions for it. Published safety studies specific to the estolide are scarce. The best available evidence comes from its starting material. The CIR Panel included meadowfoam seed oil in its assessment of 244 plant-derived fatty acid oils and found it safe in the present practices of use and concentration, and in a repeated patch test a product containing 71.3 percent meadowfoam oil did not irritate or sensitize the skin of 109 people.
On labels, this ingredient appears as Meadowfoam Estolide. The oil it is made from is listed as Limnanthes Alba (Meadowfoam) Seed Oil, and another meadowfoam-derived conditioner in our database is dimethiconol meadowfoamate.
Sources: European Commission CosIng: Meadowfoam Estolide; USDA Agricultural Research Service: Purification of meadowfoam monoestolide from polyestolide (2004); USDA Agricultural Research Service, AgResearch Magazine: Biodegradable plant-based hydraulic fluid (1998); Cosmetic Ingredient Review: Plant-derived fatty acid oils, final report for Expert Panel review (March 2011)
