Polyhydroxystearic Acid
Reviewed by Rosie · Last updated 18 Aug 2026
Often used to coat mineral sunscreen active ingredients to help them disperse evenly | Other roles in skin care include emulsion stabiliser, film-former, and texture-enhancing thickener
Addresses
EWG Safety Score
What Is Polyhydroxystearic Acid?
Polyhydroxystearic acid plays various roles in cosmetic formulas, including functioning as a suspending agent, emulsion stabilizer, film-former, and texture-enhancing thickener. This plant-derived or synthetic ingredient is often used to coat mineral sunscreen actives to help them disperse evenly. Suppliers of polyhydroxystearic acid also claim that it helps increase UV absorption and can reduce the white cast that titanium dioxide and zinc oxide leave behind.
In makeup, polyhydroxystearic acid helps pigments distribute more cohesively. In lotions and creams, it adds emolliency. As a raw material, polyhydroxystearic acid is described as a soft, pliable wax that is light tan to brown in color, derived from castor oil.
Clinical Evidence & References
Published Research
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Making Cosmetics, Accessed October 2021, ePublication [https://www.makingcosmetics.com/WAX-PHSA-01.html?lang=en_US]
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Cosmetics Business, April 2016, ePublication [https://cosmeticsbusiness.com/what-s-new-in-sun-care-filters-and-ingredients--117682]
Frequently Asked Questions
From the Clinic
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Polyglyceryl-6 Polyhydroxystearate
A synthetic emulsifier that helps blend oil and water in skincare formulations
Polyglyceryl-6 Polyricinoleate
An emulsifier derived from castor oil that helps stabilise skincare formulations
Polyglyceryl-6 Ricinoleate
Ester of polyglyceryl-6 and ricinoleic acid | Serves as an emollient and surfactant
Polyquaternium-80
A conditioning polymer that supports cleansing formulations and hair care products
Polysorbate 21
A nonionic emulsifier that stabilises oil and water-based formulations
Polysorbate 60
Widely used emulsifier made from sorbitol and stearic acid | Provides mild cleansing properties
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