What Is Peg-90 Glyceryl Isostearate?
Peg-90 Glyceryl Isostearate is a plant-derived liquid made by joining glycerin, isostearic acid from vegetable oils and about 90 units of ethylene oxide. This blend creates a gentle soap-like molecule that loves both oil and water, letting it pull grime off the skin while rinsing away with ease. The ingredient first appeared in the late 1980s when formulators searched for milder alternatives to traditional sulfates. It is produced in a two-step process: natural fats are split to get glycerin and fatty acids, then the fatty acid is reacted with glycerin and treated with ethylene oxide under controlled heat and pressure. Because the finished material is smooth, non-greasy and easy to mix, it shows up in face cleansers, micellar waters, scalp scrubs, body washes, baby washes and makeup-removing balms.
Peg-90 Glyceryl Isostearate’s Cosmetic Benefits/Uses
This ingredient is valued for its cleansing power. It lowers the surface tension between oil and water so dirt, excess sebum and makeup lift off the skin without harsh rubbing. Its large molecular size keeps it from penetrating deeply which helps it stay mild even for sensitive skin. Formulators also like that it boosts foam stability and leaves a soft after-feel so products feel comforting rather than stripped.
Who Can Use Peg-90 Glyceryl Isostearate
Because it is a mild surfactant that stays mostly on the surface of the skin Peg-90 Glyceryl Isostearate works for nearly all skin types, including dry, oily, combination and sensitive. People with a known allergy to polyethylene glycols or who have a severely compromised skin barrier may want to avoid it since any PEG based material could increase the chance of irritation in those special cases.
The raw materials come from vegetable sources and no animal by-products are used during manufacture so products using this ingredient fit vegan and vegetarian lifestyles.
No evidence suggests that Peg-90 Glyceryl Isostearate crosses the skin in meaningful amounts or affects hormone levels which means it is generally considered safe for women who are pregnant or breastfeeding. This is not medical advice and anyone who is pregnant or nursing should ask a healthcare professional before starting new skincare just to be on the safe side.
The ingredient does not increase photosensitivity so it will not make skin more prone to sunburn. It is also nonionic so it plays nicely with most actives, preservatives and fragrances commonly found in cleansers.
Potential Side Effects/Adverse Reactions
Reactions to topical Peg-90 Glyceryl Isostearate differ from person to person. The points below list potential side effects, but these outcomes are uncommon when the ingredient is used at standard levels in well-formulated products.
- Mild stinging or redness short-lived transient warmth can occur in very sensitive skin especially if the formula sits too long before rinsing
- Contact dermatitis rare allergy to PEGs or residual impurities may trigger itching or rash
- Eye irritation if the cleanser accidentally gets into the eyes it can cause temporary watering or burning
- Excess dryness over-cleansing multiple times a day might strip natural oils leading to tightness or flaking
- Breakouts in highly acne-prone skin although unlikely some individuals report small bumps when any PEG fatty ester is left on the skin without thorough rinsing
If irritation or any unexpected reaction develops stop using the product and consult a healthcare professional
Comedogenic Rating
Rating: 1/5 Peg-90 Glyceryl Isostearate is a large, water-loving molecule that mostly sits on the skin surface and rinses away, so it has little chance to lodge inside pores and trigger blockages. No studies report a high rate of clogging or breakouts linked to this specific surfactant, which is why it earns a low score. It is generally suitable for acne-prone or breakout-prone skin, provided the overall formula is oil light and properly rinsed. Published data on its pore-clogging potential are sparse, but the available evidence and practical experience point to minimal risk.
Summary
Peg-90 Glyceryl Isostearate is used mainly as a mild cleanser that loosens dirt, oil and makeup then rinses clean, thanks to its dual love of water and oil. Its sizeable molecular structure keeps it gentle, helps stabilize foam and leaves skin feeling soft rather than squeaky.
While it is not as famous as sulfates or the newer amino acid surfactants, you will still spot it in a fair share of micellar waters, facial washes and baby cleansers aimed at sensitive users who want effective yet mild cleansing.
Safety studies and decades of use show low irritation potential, no evidence of hormone disruption and negligible likelihood of clogging pores. As with any cosmetic ingredient, do a quick patch test when trying a new product so you can catch any personal sensitivities early.