Peg-120 Methyl Glucose 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
Share:
Inside this article:

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-120 Methyl Glucose Triisostearate?

Peg-120 Methyl Glucose Triisostearate is a plant-sourced ingredient created by linking glucose from corn or sugar beet with isostearic acid derived from coconut or soybean oil, then attaching about 120 units of ethylene oxide. The result is a large molecule that loves both oil and water, giving it a natural talent for thickening watery formulas. Chemists first explored this material in the late 1990s when brands were looking for gentler nonionic thickening agents that could replace harsher synthetic gums. Production starts with methyl glucose, which is esterified with isostearic acid to form a triester. This triester then undergoes controlled ethoxylation, where ethylene oxide gas is added under heat and pressure until the average chain length reaches 120 units. The finished ingredient is a clear viscous liquid that dissolves easily in water, disperses oils and boosts texture.

Its ability to build body without making a formula sticky means you will often spot it in facial cleansers, micellar waters, shower gels, shampoos, sheet mask serums, leave-on conditioners, lightweight moisturizers, anti aging creams, makeup removers and even some styling products.

Peg-120 Methyl Glucose Triisostearate’s Cosmetic Benefits/Uses

In skincare and haircare formulas this ingredient mainly shines as a texture enhancer.

Viscosity controlling: It thickens watery bases so the product feels rich and cushy, stays where you apply it and pours out of the bottle at just the right speed. By fine-tuning flow it also keeps tiny oil droplets, pigments or actives evenly suspended, which helps the formula stay stable over its shelf life and ensures each use delivers consistent results.

Who Can Use Peg-120 Methyl Glucose Triisostearate

This gentle thickener is generally well tolerated by all skin types including oily, combination, dry and sensitive skin because it is nonionic and has a very low risk of clogging pores or upsetting the skin’s barrier.

Its raw materials come from corn or sugar beet and coconut or soybean oil, so it is suitable for vegans and vegetarians as long as the finished formula contains no other animal sourced ingredients.

The molecule stays mainly on the skin surface and has no known hormonal activity, so it is considered low concern for pregnant or breastfeeding women. This is not medical advice and expectant or nursing users should still ask their doctor before adding any new product to their routine.

Peg-120 Methyl Glucose Triisostearate does not increase photosensitivity and you do not need extra sun protection beyond your usual daily sunscreen.

Potential Side Effects/Adverse Reactions

Reactions to topical Peg-120 Methyl Glucose Triisostearate differ from person to person. The points below list potential side effects that may occur, though they are uncommon when the ingredient is used at typical levels in well formulated products.

  • Mild skin irritation such as redness or itching, usually in very sensitive individuals or when used in high concentration
  • Allergic contact dermatitis in people with a specific sensitivity to polyethylene glycol derivatives
  • Transient eye stinging if a cleanser or shampoo containing the ingredient accidentally gets into the eyes before rinsing
  • Dry or tight feeling if a formula contains little to no additional moisturizers and the user has very dry skin

If you experience persistent discomfort stop using the product and seek guidance from a healthcare professional.

Comedogenic Rating

Rating: 0 / 5

Peg-120 Methyl Glucose Triisostearate earns a zero because its bulky water-loving structure sits on the skin surface, mixes readily with water and leaves minimal oily residue so it does not block pores. It is classed as a nonionic surfactant–thickener rather than an oil or butter and has no record of triggering comedones in published cosmetic safety data.

That makes it suitable for people who are prone to acne or breakouts.

As with any polyethylene glycol derivative, an extremely small group of users with existing sensitivity to PEGs could still experience irritation, which is unrelated to clogged pores.

Summary

Peg-120 Methyl Glucose Triisostearate is mainly a viscosity controller that thickens watery formulas so cleansers, toners and hair products feel luxurious, stay stable and dispense smoothly. Its long chain of ethylene oxide units lets it dissolve in water while its isostearic acid section grabs hold of oils, giving chemists an easy way to fine-tune texture without heavy gums.

The ingredient is moderately popular, turning up most often in gentle facial cleansers and lightweight shampoos where brands want a plant-sourced alternative to synthetic thickeners.

Current safety reviews find it non-comedogenic, low risk for irritation and free of hormone-disrupting activity. Even so, everyone’s skin is unique so it is smart to patch test any new product that contains it before full use.

Was this article helpful?
More from Glooshi:
ADVERTISEMENT
Get all our top headlines in beauty.
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Get the latest beauty news, top product recommendations & brand-exclusive discount codes direct to your inbox.
Send good feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send bad feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Search