Glyceryl Undecylenate in Skincare: What It Does and Why We Use It

Glyceryl undecylenate is a supporting player: a glycerine-based ester that helps a cream feel soft and stay blended. It's easy to mix up with undecylenic acid, but they're different ingredients, and the antifungal research belongs to the acid, not this one.

What is glyceryl undecylenate?

Glyceryl undecylenate (INCI: Glyceryl Undecylenate) is a monoglyceryl monoester. That means one fatty acid, undecylenic acid, is attached to one glycerine backbone.

The CIR report defines it as "the ester of glycerin and undecylenic acid" and lists its functions as skin conditioning agent (emollient) and surfactant (emulsifying agent). Its molecular weight is about 258 Da.

It's easy to confuse with two other things, so here's the short version.

• Undecylenic acid is the parent acid. It's the one with published antifungal research. An ester is a different molecule, and that research doesn't transfer to it.
• Glyceryl caprylate is a different monoglyceride, made from a shorter fatty acid (caprylic acid). Similar family, different ingredient.

What does glyceryl undecylenate do for skin?

In a formula, glyceryl undecylenate sits in the oil and water interface. As an emollient it helps leave skin feeling smoother and softer.

As an emulsifying surfactant it helps oil and water phases stay blended in a cream or lotion. Those are the functions the CIR report records for it.

Some suppliers also describe it as supporting preservation. That's not something we claim for it, and we don't claim any antimicrobial effect.

Why we use glyceryl undecylenate

It's in our Retinol & Peptide Night Repair Cream. Our formulator includes it as part of the cream's supporting cast, alongside the other texture ingredients.

Our view: you don't notice an ingredient like this when it's doing its job. You just notice a cream that feels soft and stays smooth.

Who is glyceryl undecylenate good for?

Most people meet glyceryl undecylenate as one ingredient among many in a moisturiser. Anyone can react to any ingredient, though, and no ingredient is guaranteed to be tolerated by everyone. Be more careful if your skin is reactive or you have a known sensitivity to fatty acid derivatives or to undecylenic acid itself.

If you're unsure, patch test first. Our guide to how to patch test skincare properly walks through it. If you have a skin condition or you're pregnant or breastfeeding, check your full routine with your doctor or pharmacist.

How do you use it?

You don't apply glyceryl undecylenate on its own. It's a formula ingredient, not a stand-alone treatment.

You use it by using the finished product it sits in, following that product's directions. Apply to clean skin, and stop use if irritation develops.

What does it pair with?

As a supporting emollient and emulsifier, it sits alongside humectants, other emollients and thickeners without special rules. Ingredients you'll often see in the same kinds of creams include glycerine, cetyl alcohol and xanthan gum.

There's no known ingredient that must be avoided with it. What matters is the overall routine: if you layer several active products, introduce one at a time so you can tell what your skin is responding to.

What does the research say?

The short version: reviewed as a group, with little research on this ester by itself.

The CIR monoglyceryl monoesters report is the main safety document, and it assesses the group as a class (Fiume et al., 2020).

The antifungal research is about the parent acid. A laboratory study found undecylenic acid reduced germ tube formation in Candida albicans about sevenfold at 10 mM without affecting growth rate (McLain et al., 2000). That's a laboratory finding on undecylenic acid, not on glyceryl undecylenate, and not on any finished skincare product.

Safety and regulation

CIR (United States). The CIR Expert Panel assessed 44 monoglyceryl monoesters together, and glyceryl undecylenate is named in that list.

The Panel concluded that these ingredients are safe in cosmetics in the present practices of use and concentration (Fiume et al., 2020). The report records only a very small number of reported uses of glyceryl undecylenate and no maximum leave-on concentration for it, so there's no figure to quote.

EU. Annex V of the EU Cosmetics Regulation (1223/2009), the list of permitted preservatives, includes "Undec-10-enoic acid and its salts" at a maximum of 0.2% (as acid).

That entry covers the acid and its salts such as sodium and potassium undecylenate. In the consolidated Annex V text, glyceryl undecylenate is not named.

Glyceryl undecylenate in Dope Skin Co products

It appears in the full ingredient list of the Retinol & Peptide Night Repair Cream. Not sure what your skin needs? Take the skincare quiz.

Frequently asked questions

Is glyceryl undecylenate the same as undecylenic acid?
No. Undecylenic acid is the parent fatty acid. Glyceryl undecylenate is that acid joined to glycerine as an ester. They're different ingredients with different documented uses.

Is glyceryl undecylenate antifungal?
The antifungal research is on undecylenic acid, not the ester. We don't claim antifungal effects for glyceryl undecylenate or for any finished product.

Is it a preservative?
The CIR report lists it as a skin conditioning emollient and emulsifying surfactant. Some suppliers describe it as supporting preservation, but it isn't named in the EU preservatives list.

Is it the same as glyceryl caprylate?
No. Glyceryl caprylate is made from caprylic acid, a shorter fatty acid. Both are monoglycerides, but they're separate ingredients.

Has it been safety reviewed?
Yes, as part of the CIR assessment of monoglyceryl monoesters, which concluded these ingredients are safe as used in cosmetics.

Related ingredients

If you're reading about supporting ingredients, these entries may help: ethylhexylglycerin, cetearyl olivate, sorbitan olivate and retinol. You can see it in context in the Retinol & Peptide Night Repair Cream.

Sources

• Fiume MM, Bergfeld WF, Belsito DV, et al. (Cosmetic Ingredient Review Expert Panel). Safety Assessment of Monoglyceryl Monoesters as Used in Cosmetics. International Journal of Toxicology 2020;39(3_suppl). SAGE Journals.
• McLain N, Ascanio R, Baker C, Strohaver RA, Dolan JW. Undecylenic Acid Inhibits Morphogenesis of Candida albicans. Antimicrobial Agents and Chemotherapy 2000;44(10):2873-2875. ASM Journals.
• Regulation (EC) No 1223/2009 on cosmetic products, Annex V (list of preservatives), entry for Undec-10-enoic acid and its salts. Consolidated text, legislation.gov.uk.