What Is Polyglyceryl-2 Sesquiisostearate?
Polyglyceryl-2 Sesquiisostearate is a plant-derived ingredient made by linking glycerin molecules and then attaching them to isostearic acid, a fatty acid usually sourced from vegetable oils like rapeseed or soybean. Chemically it is an ester, meaning it combines an alcohol base (glycerin) with a fatty acid, creating a substance that can mix oil and water. Interest in this kind of mild, nonionic emulsifier grew in the late 1990s when brands looked for alternatives to petroleum-based surfactants. Manufacturers produce it through a two-step process: first they polymerize glycerin through heating to create polyglycerin-2, then they perform esterification by reacting it with isostearic acid under controlled heat and vacuum. The result is a soft, waxy material that melts easily into cosmetic formulas. You will most often find it in makeup removers, cleansing oils, moisturizing creams, sunscreens, BB creams and nourishing masks where a stable oil-in-water blend is essential.
Polyglyceryl-2 Sesquiisostearate’s Cosmetic Benefits/Uses
This ingredient mainly serves as an emulsifier. By sitting at the boundary between oil and water phases it helps disperse oils into tiny droplets, creating a smooth stable mixture that feels light and non-greasy on the skin. A good emulsion improves spreadability, ensures even delivery of active ingredients and prevents the product from separating on the shelf, which in turn extends shelf life and maintains a pleasant texture.
Who Can Use Polyglyceryl-2 Sesquiisostearate
This mild plant based emulsifier works well for most skin types. Dry and normal skin appreciate the light occlusive layer it leaves behind while sensitive skin benefits from its gentle nonionic nature that rarely stings or burns. Combination skin usually tolerates it without issue. Those with very oily or acne prone skin can use it too but might prefer lower concentrations because its fatty backbone can feel slightly rich if a formula is already heavy in oils.
The ingredient is made from vegetable glycerin and plant sourced isostearic acid so it suits both vegans and vegetarians. No animal derivatives or animal testing are required for its production when sourced from reputable suppliers.
Current safety data show no special risks for pregnant or breastfeeding women. Still this is not medical advice; anyone who is expecting or nursing should have a doctor review all skincare products before use just to be safe.
Polyglyceryl-2 Sesquiisostearate does not make skin more sensitive to sunlight and has no known photo-reactive properties. It is also free of common fragrance allergens and is not a known endocrine disruptor.
Potential Side Effects/Adverse Reactions
Reactions to topical Polyglyceryl-2 Sesquiisostearate differ from person to person. The following is a list of potential side effects only, and most users will never notice any of them when the ingredient is used correctly in a finished product.
- Mild redness or irritation in those with extremely reactive skin
- Temporary clogged pores if used in a very high oil load formula on acne prone skin
- Rare allergic contact dermatitis in individuals sensitive to fatty acid esters
If any discomfort, rash or unexpected reaction appears stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1 / 5
Polyglyceryl-2 Sesquiisostearate is built on glycerin, a non-clogging humectant, and isostearic acid, a branched fatty acid that is less likely to pack tightly in pores than straight-chain oils. In finished formulas it is usually used at low levels to stabilize oil droplets, so the overall chance of it blocking pores is low.
Suitable for acne-prone or breakout-prone skin in most cases, especially when the rest of the product is light and well balanced.
Keep in mind that the total oil load, the presence of other heavier lipids and how thoroughly the product is rinsed off can raise or lower the real-world clogging risk.
Summary
Polyglyceryl-2 Sesquiisostearate is mainly an emulsifier that keeps oil and water blended, giving creams and cleansers a smooth stable texture. It does this by anchoring its water-loving glycerin side in the aqueous phase while its fatty side holds on to oils, creating tiny droplets that stay suspended.
It has found steady use in cleansing oils, balms, BB creams and sunscreens but it is not as famous as classic emulsifiers like polysorbates. Brands that favor plant-based or mild alternatives often choose it for its gentle feel and vegan origin.
Current safety data rate it as very low risk with few reports of irritation or allergy. As with any new skincare product it is smart to patch test first to check personal tolerance.