What Is Peg-3 Glyceryl Triisostearate?
Peg-3 Glyceryl Triisostearate is a synthetic ingredient created by attaching three units of polyethylene glycol (PEG-3) to glyceryl triisostearate, an ester formed from glycerin and isostearic acid, a branched fatty acid usually sourced from vegetable oils. Chemists first explored PEG-based esters in the mid-20th century while looking for ingredients that could soften skin and help oil and water mix. Over time this material proved especially useful because it combines the skin-cushioning feel of fatty acids with the water-friendly nature of PEG.
Manufacturing starts with glycerin reacting with isostearic acid to form glyceryl triisostearate. That ester then undergoes controlled ethoxylation, adding on average three ethylene oxide units to each glycerol backbone. The result is a molecule that has both oil-loving and water-loving parts, making it ideal for modern skin care formulas.
You will commonly find Peg-3 Glyceryl Triisostearate in rich face creams, body lotions, cleansing balms, makeup removers, stick foundations, sun care products and leave-on hair conditioners where it helps create a smooth, even texture.
Peg-3 Glyceryl Triisostearate’s Cosmetic Benefits/Uses
This ingredient pulls double duty in formulas
- Emollient: Adds a silky cushion that smooths rough patches, reduces moisture loss and gives products a creamy glide so they spread easily
- Emulsifying: Helps oil and water stay blended which keeps creams stable, prevents separation and ensures active ingredients are delivered evenly with each use
Who Can Use Peg-3 Glyceryl Triisostearate
This multitasking emollient suits most skin types. Its light occlusive film helps dry or mature skin retain moisture yet does not feel overly greasy, so balanced and slightly oily skin usually tolerates it as well. Those with very oily or acne-prone skin might prefer lighter textures because the fatty nature of the molecule could feel heavy in thick formulations, though it is not considered highly pore-clogging by itself.
The ingredient is synthesized from glycerin and plant-derived isostearic acid then reacted with ethylene oxide, so no animal-sourced materials are involved. That makes it appropriate for vegans and vegetarians provided the finished formula also avoids animal derivatives.
No research indicates Peg-3 Glyceryl Triisostearate poses specific risks during pregnancy or while breastfeeding when used on intact skin. Still this is not medical advice and anyone who is pregnant or nursing should review all personal care products with a qualified healthcare professional to be safe.
The molecule does not absorb UV light or make skin more sensitive to sunlight, so it is not linked to photosensitivity. It is also fragrance-free and nonvolatile which lowers the chance of airborne irritation.
Potential Side Effects/Adverse Reactions
Responses to topical Peg-3 Glyceryl Triisostearate vary from person to person. The effects listed below are potential outcomes and are not expected for the average user when the ingredient is properly formulated and used as directed.
- Mild skin irritation such as redness or stinging in individuals with very sensitive skin
- Rare allergic contact dermatitis resulting in itching or small rash
- Eye irritation if the product accidentally enters the eyes
- Increased penetration of other ingredients if the formula includes impurities that have not been adequately removed
- Heavy or greasy feel in some users with extremely oily skin types
If any discomfort or adverse reaction occurs stop use immediately and consult a healthcare professional if symptoms persist or worsen.
Comedogenic Rating
Rating: 2 / 5
Peg-3 Glyceryl Triisostearate contains branched isostearic acid which is less likely to block pores than straight-chain fatty acids, and the PEG portion increases its water affinity so it tends to rinse away more easily. Still, it is an oil-derived emollient so at higher levels or in very rich formulas it can sit on the skin longer, giving it a low-to-moderate potential to clog pores. It is generally acceptable for people who are prone to acne or breakouts, especially in lightweight products, though very reactive or severely oily skin may prefer leaner options.
If paired with heavier occlusives or used in thick balms the overall formula could be more pore-clogging than the ingredient alone, so look at the full ingredient list rather than this material in isolation.
Summary
Peg-3 Glyceryl Triisostearate works mainly as an emollient and an emulsifier. The fatty ester side cushions skin leaving it softer while the PEG units attract water and help oil and water mingle so creams stay smooth and stable.
It is a solid mid-tier helper in skin care and makeup rather than a headline act, showing up most often in moisturizers makeup removers and creamy sunscreens where it boosts texture without driving up cost.
Safety data and decades of cosmetic use show a very low risk profile with only rare irritation or allergy reports. As with any new product it is best to patch test first to be sure your skin agrees with the full formula.