What Is Polyglyceryl-6 Undecylenate?
Polyglyceryl-6 Undecylenate is a plant-derived compound created by linking six glycerin molecules, then attaching them to undecylenic acid, a fatty acid traditionally sourced from castor oil. The resulting ester is water-loving at one end and oil-loving at the other, a structure that makes it ideal for bringing oil and water together. Interest in the ingredient grew in the early 2010s as brands started searching for biodegradable, PEG-free emulsifiers that could satisfy clean beauty standards. Production involves first heating glycerin under vacuum so the molecules join into a small chain of six units, then reacting this chain with undecylenic acid to form the final ester. The finished ingredient appears as a clear to pale yellow liquid that slips easily into many formulas. You will spot it in moisturizers, sunscreens, cleansing oils, makeup removers, serums, masks and baby care products where a stable, smooth texture is essential.
Polyglyceryl-6 Undecylenate’s Cosmetic Benefits/Uses
This ingredient is prized for one key job in topical products: emulsifying. By sitting at the boundary between oil and water, it keeps the two phases from separating so creams and lotions stay uniform from the first pump to the last. A good emulsifier improves spreadability, boosts the light feel of a formula and helps active ingredients distribute evenly across the skin. Because undecylenic acid has mild antifungal properties, the emulsifier can also lend a touch of supporting preservation, which lets brands reduce the level of traditional preservatives in a formula.
Who Can Use Polyglyceryl-6 Undecylenate
Thanks to its gentle nature and low likelihood of clogging pores, Polyglyceryl-6 Undecylenate is generally suitable for dry, normal, combination, oily and even sensitive skin. Its light texture does not leave a greasy film, making it a comfortable option for acne-prone or easily congested complexions. No specific skin type needs to steer clear, though anyone with a known allergy to castor-derived ingredients should approach with caution.
The ester is plant based, produced from vegetable glycerin and castor oil, so it aligns with vegan and vegetarian preferences. It is also biodegradable, which appeals to users seeking eco-conscious formulas.
Current safety data shows no reproductive or developmental concerns, so products containing this emulsifier are considered acceptable for pregnant or breastfeeding women when used topically. That said, this is not medical advice and individuals who are pregnant or nursing should run any skincare choices past a qualified health professional to be on the safe side.
Polyglyceryl-6 Undecylenate is not known to cause photosensitivity, so daytime use does not increase the risk of sunburn. As with any skincare ingredient, compatibility depends on the full formula and the user’s unique skin.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Polyglyceryl-6 Undecylenate can vary person to person. The points below outline potential reactions, but they are uncommon when the ingredient is used correctly in a well-formulated product.
- Mild redness or irritation in very sensitive skin
- Contact dermatitis in individuals allergic to castor-derived materials
- Temporary stinging if applied to broken or compromised skin
- Eye irritation if the product accidentally gets into the eyes
If any of these effects occur discontinue use and consult a healthcare professional.
Comedogenic Rating
Rating: 1/5 (very low)
Polyglyceryl-6 Undecylenate is a large, water-friendly ester that spreads thinly and rinses off easily, so it is unlikely to settle in pores and encourage blockages. Its fatty acid tail is balanced by six glycerin units that boost solubility and reduce the heavy, waxy feel linked with higher-rated emulsifiers. As a result, the ingredient earns a near-non-comedogenic score.
This low rating means the ester is generally suitable for people who are prone to acne or frequent breakouts.
Keep in mind that the overall comedogenic potential of a finished product depends on the full formula, application amount and individual skin chemistry.
Summary
Polyglyceryl-6 Undecylenate works mainly as an emulsifier, uniting oil and water so creams and lotions stay smooth and stable. Its dual-natured structure — a glycerin-rich head attached to an undecylenic acid tail — lets it sit at the oil-water boundary and keep phases mixed while adding a light, silky glide.
The ingredient has gained traction with clean beauty and baby care brands looking for biodegradable PEG-free options, though it remains a niche choice compared with older emulsifiers.
Current research shows it is gentle, largely non-comedogenic and safe for most skin types when used as directed. As with any new skincare ingredient, perform a quick patch test before fully incorporating products containing Polyglyceryl-6 Undecylenate into your routine to ensure personal compatibility.