Peg-30 Glyceryl Triisostearate: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Peg-30 Glyceryl Triisostearate?

Peg-30 Glyceryl Triisostearate is a fatty acid ester made by joining glycerin, isostearic acid derived from vegetable oils like soybean or coconut, and about 30 units of polyethylene glycol. The final molecule looks like a three armed structure: each arm is a softening isostearic acid chain while the center holds water loving PEG segments. This mix of oily and watery parts lets the ingredient bridge the gap between oils and water.

Scientists began exploring PEG based esters in the 1960s as safer, milder alternatives to harsh soaps. As cosmetic formulas grew more sophisticated through the 1980s brands adopted Peg-30 Glyceryl Triisostearate for its gentle skin feel and ability to keep mixtures stable for long periods.

Production starts with natural fats that are split to yield isostearic acid. The acid is then reacted with glycerin to form glyceryl triisostearate. Finally ethylene oxide gas passes over the ester under controlled heat and pressure, attaching roughly 30 PEG units to each molecule. The result is a creamy, wax like substance that dissolves in oil yet disperses in water.

You will usually spot Peg-30 Glyceryl Triisostearate in cleansing balms, makeup removers, moisturizing creams, sun care products, hair conditioners, sheet mask essences and many rich baby care lotions.

Peg-30 Glyceryl Triisostearate’s Cosmetic Benefits/Uses

This multitasker brings two main advantages to a formula

  • Emollient – coats the skin or hair with a thin fatty layer that softens, smooths and helps reduce moisture loss giving a supple feel without heaviness
  • Emulsifying – helps oil and water blend into a stable cream or lotion so the product stays uniform, spreads evenly and delivers active ingredients more consistently

Who Can Use Peg-30 Glyceryl Triisostearate

Because it is both lightweight and cushioning Peg-30 Glyceryl Triisostearate fits most skin types including dry, normal and combination skin. Sensitive skin usually tolerates it well thanks to its low irritation profile yet those with very oily or acne-prone skin might find rich formulas containing high levels of this ester feel too occlusive.

The ingredient is manufactured from plant based fatty acids and petro-derived ethylene oxide rather than animal sources so it is suitable for vegans and vegetarians.

No research points to problems for pregnant or breastfeeding women when this ingredient is used topically at cosmetic levels. Absorption through intact skin is minimal. Still this is not medical advice and anyone who is expecting or nursing should run their routine by a qualified health professional to be safe.

Peg-30 Glyceryl Triisostearate does not make skin more sensitive to sunlight and has no known interactions with UV exposure.

Potential Side Effects/Adverse Reactions

Responses to topical Peg-30 Glyceryl Triisostearate vary from person to person. The issues listed below are possible yet unlikely when the ingredient is used correctly in a well-formulated product.

  • Mild redness or stinging
  • Contact dermatitis in individuals allergic to polyethylene glycols
  • Temporary eye irritation if the product accidentally gets into the eyes
  • Clogged pores or breakout flare-ups in some acne-prone users when used in heavy concentrations
  • Heightened penetration of other actives which could amplify their irritancy on compromised skin

If any discomfort or persistent reaction occurs discontinue use and seek advice from a healthcare professional.

Comedogenic Rating

2 / 5. Peg-30 Glyceryl Triisostearate has long fatty acid chains that can sit on the skin surface, yet its attached PEG units make the molecule more water dispersible so it is less likely to lodge deep inside pores than pure plant oils or waxes. Most users will not notice clogged pores at the modest levels typically found in cleansers and lotions, though very oily or congestion-prone skin might react if the overall formula is rich or layered with other heavy ingredients. In short, it is generally fine for acne-prone skin but not the safest pick when used in high concentrations.

Keep in mind that comedogenicity is influenced by the whole formulation, the amount applied and how thoroughly the product is rinsed or removed.

Summary

Peg-30 Glyceryl Triisostearate acts as an emollient and an emulsifier. Its fatty isostearic arms smooth and soften while its PEG spine grabs onto water so it can pull oil and water phases together into a stable blend that feels silky rather than greasy. Because of this dual nature it shows up in cleansing balms, nourishing creams and sunscreens, though it is not as universally used as classics like glyceryl stearate or cetearyl alcohol.

Current data labels it low risk for irritation, sensitization or toxicity when used at cosmetic levels. Still, every skin is unique so it is smart to patch test any new product that contains it just to be safe.

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