What Is Polyglyceryl-3 Triisostearate?
Polyglyceryl-3 Triisostearate is a plant-derived ingredient created by linking three glycerin molecules to isostearic acid, a branched fatty acid most often sourced from vegetable oils such as rapeseed or soybean. The result is a mild lipid that feels cushiony on the skin and blends easily with both oils and water-based ingredients.
Chemists began exploring polyglyceryl esters in the 1990s when brands started looking for alternatives to petroleum-based surfactants. Because the raw materials are renewable and the final molecule is biodegradable Polyglyceryl-3 Triisostearate quickly gained popularity in natural and mainstream formulas alike.
The ingredient is produced through a two-step process. First glycerin undergoes controlled heating to form polyglycerin-3. This is then reacted with isostearic acid in an esterification step that removes water and bonds the two components. The resulting liquid is clear to pale yellow and has a velvety, non-greasy feel.
You will usually find Polyglyceryl-3 Triisostearate in products that need to melt away makeup or deliver rich moisture without heaviness. Common examples include cleansing balms, cream and stick foundations, lipsticks, tinted balms, nourishing face oils, moisturizers and baby care formulas.
Polyglyceryl-3 Triisostearate’s Cosmetic Benefits/Uses
This multitasking ingredient improves both the feel and stability of a wide range of formulas.
- Emollient – softens and smooths the skin surface, creating a supple after-feel that helps lock in hydration
- Emulsifying – allows water and oil to mix, giving creams, lotions and balms a uniform texture that stays stable over time
Who Can Use Polyglyceryl-3 Triisostearate
With its lightweight cushiony feel Polyglyceryl-3 Triisostearate generally suits all skin types including oily, combination, normal and dry. Sensitive skin usually tolerates it well because the molecule is large and nonpenetrating, which means it is far less likely to trigger stinging or redness. Acne-prone users may also find it compatible since it helps dissolve excess oil without leaving a heavy residue, though individual reactions can vary.
The ingredient is derived from vegetable glycerin and plant oils so it is appropriate for both vegans and vegetarians. No animal by-products are used at any point in its manufacture.
Current research shows no specific risks for pregnant or breastfeeding women when the ingredient is applied topically in cosmetics. This is not medical advice and anyone who is expecting or nursing should run any skincare product past a qualified doctor to be on the safe side.
Polyglyceryl-3 Triisostearate does not make skin more sensitive to sunlight and it is stable under UV exposure, so there is no heightened need for sun-related precautions beyond everyday sunscreen use.
Potential Side Effects/Adverse Reactions
Side effects from topical Polyglyceryl-3 Triisostearate differ from person to person. The following are potential reactions only and are unlikely for most users when the ingredient is used correctly in a finished product.
- Mild redness or irritation in very reactive skin
- Temporary clogged pores if applied in excess on extremely oily skin
- Allergic contact dermatitis in individuals sensitive to fatty acid esters (rare)
If you notice any discomfort, stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1/5
Polyglyceryl-3 Triisostearate sits at the low end of the scale because its bulky structure makes it less likely to settle inside pores and it often rinses away cleanly when used in cleansing formulas. It melts into a thin layer rather than forming a thick film, which further lowers the chance of buildup. Most people who deal with acne or frequent breakouts find it acceptable, but extremely oily skin may want to monitor how much of it is layered on at once.
Keep in mind that a finished product’s overall comedogenic potential also depends on the other oils, waxes and pigments in the formula, plus how heavily it is applied.
Summary
Polyglyceryl-3 Triisostearate acts as both an emollient and an emulsifier. It softens and cushions skin by laying down a light fatty layer, while its ability to link water with oil keeps creams, balms and makeup from separating. These dual talents make it a favorite in cleansing balms, stick foundations, lip products and gentle baby care even though it has not reached the household name status of ingredients like glycerin or shea butter.
Safety data and real-world use show it is generally well tolerated, non-sensitizing and vegan friendly. As with any new skincare ingredient it is wise to do a small patch test the first time you try a product that contains it so you can spot any personal sensitivities early.