44 glyceryl esters judged safe as used in cosmetics
Fiume 2020, Int J Toxicol · Source
Glyceryl Caprylate & Glyceryl Undecylenate
Plant-derived, from coconut and castor · certified organic
A gentle, plant-derived pair that keeps the Toner fresh without parabens or alcohol. Each joins glycerin to a natural fatty acid from coconut or castor oil.
44related ingredients reviewed and found safe in cosmetics
Plant-derivedfrom coconut and castor oils
Paraben-freeand alcohol-free freshness
Why we love it
Any water-based product needs protection from spoilage once it's opened. We chose this pair because they come from plants, are widely used in natural and organic cosmetics, and are gentle at the low levels used.
What does the research show?
Safety
An independent expert panel, the Cosmetic Ingredient Review, assessed 44 ingredients in this family in 2020 and found them safe as used in cosmetics.
How they work together
On its own, glyceryl caprylate is a mild preservative. Pairing it with glyceryl undecylenate broadens its protection, which is why the two are used together.
Related research
A close relative, glyceryl laurate (monolaurin), has been studied in a vaginal gel without changing vaginal pH or lactobacilli. That is a different ingredient, used at a different level.
Studies
Human study tested in people Lab study a starting point, not proof
Glyceryl caprylate alone has mild preservative activity
Loo 2010, J Oil Palm Res · Source
Glyceryl laurate vaginal gel did not change vaginal pH or lactobacilli
Strandberg 2010, Antimicrob Agents Chemother · Source
Undecylenic acid, the castor-derived fatty acid in glyceryl undecylenate, stopped Candida albicans from switching to its invasive thread-like form
McLain 2000, Antimicrob Agents Chemother · Source
How has it been used traditionally?
Both are widely used in natural cosmetics as alternatives to synthetic preservatives.
Are they safe on my skin?
An independent expert panel found this family of ingredients safe as used in cosmetics, and they make up a very small part of the Toner. They're made from coconut and castor, so if you have a coconut allergy, ask us for details.
Last reviewed: November 2026.
Found in
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Reviewed by the Momotaro Apotheca medical team, including OB-GYNs and naturopathic doctors. Educational information, not medical advice. All ingredient research