Ingredient review
PEG-90 Glyceryl Isostearate
INCI: PEG-90 Glyceryl Isostearate
A reliable synthetic emulsifier that helps create smooth, stable formulas, but its PEG component raises mild environmental and purity concerns.
In plain English
PEG-90 Glyceryl Isostearate is a man-made ingredient that acts like a bridge between oil and water. In skincare, it helps mix ingredients that normally don't combine, like oil and water, so your lotion or cream stays smooth and doesn't separate. The 'PEG' part stands for polyethylene glycol, a chain of molecules that helps the ingredient dissolve easily. While it's generally considered safe in small amounts, some people prefer to avoid PEGs due to concerns about potential impurities from manufacturing.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-90 Glyceryl Isostearate is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging PEG-90 Glyceryl Isostearate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic emulsifier made by attaching a chain of 90 ethylene oxide units (PEG) to glyceryl isostearate, a fatty acid derivative. It is a waxy solid at room temperature and is designed to stabilize oil-and-water mixtures.
How it works
It reduces the surface tension between oil and water, allowing them to blend into a uniform, stable emulsion. This prevents your product from separating into layers and gives it a smooth, creamy texture that spreads easily on skin.
Pros
Excellent emulsifier
It creates very stable oil-and-water blends, so your lotion or cream won't separate over time, keeping the texture consistent from first use to last.
Low irritation risk
PEG-90 Glyceryl Isostearate has a low irritation profile, making it suitable for most skin types, including sensitive skin, when used at typical concentrations.
Cons and cautions
Potential impurities
During manufacturing, PEG compounds can form trace amounts of 1,4-dioxane, a possible carcinogen. However, reputable brands purify their ingredients to remove these impurities.
Not biodegradable
This synthetic ingredient does not break down easily in the environment, which may be a concern for eco-conscious consumers.
Best for
- People who enjoy lightweight, non-greasy creams and lotions
- Those with normal to combination skin looking for stable, everyday moisturizers
Use caution if
- Individuals who strictly avoid all PEG-derived ingredients due to personal preference or environmental concerns
Usage tips
Safety summary
PEG-90 Glyceryl Isostearate is considered safe for use in cosmetics at typical concentrations. The main concern is the potential for trace impurities like 1,4-dioxane, but these are controlled by quality manufacturing. It has low skin irritation and comedogenic ratings.
Research notes
The Cosmetic Ingredient Review (CIR) panel has evaluated PEG compounds and found them safe for use in cosmetics when formulated to minimize impurities. No specific studies on PEG-90 Glyceryl Isostearate alone were found, but the class of PEG glyceryl esters is well-studied and considered low-risk.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission, with no concentration restrictions in most countries. Manufacturers are expected to follow good manufacturing practices to limit impurities.
- Common uses
- Moisturizers, Cleansers, Sunscreens, Makeup removers
- Environmental note
- PEG compounds are not readily biodegradable and can persist in water systems. Some brands are moving toward biodegradable alternatives to reduce environmental impact.
Good to know
- The number '90' refers to the length of the PEG chain, which affects how water-soluble the ingredient is.
- PEG-90 Glyceryl Isostearate is often used in 'water-in-oil' emulsions, which are thicker and more moisturizing than oil-in-water types.
Common questions
What is PEG-90 Glyceryl Isostearate in beauty products?
PEG-90 Glyceryl Isostearate is a man-made ingredient that acts like a bridge between oil and water. In skincare, it helps mix ingredients that normally don't combine, like oil and water, so your lotion or cream stays smooth and doesn't separate. The 'PEG' part stands for polyethylene glycol, a chain of molecules that helps the ingredient dissolve easily. While it's generally considered safe in small amounts, some people prefer to avoid PEGs due to concerns about potential impurities from manufacturing.
What does PEG-90 Glyceryl Isostearate do in a beauty product?
It reduces the surface tension between oil and water, allowing them to blend into a uniform, stable emulsion. This prevents your product from separating into layers and gives it a smooth, creamy texture that spreads easily on skin.
Is PEG-90 Glyceryl Isostearate safe for most people?
PEG-90 Glyceryl Isostearate is considered safe for use in cosmetics at typical concentrations. The main concern is the potential for trace impurities like 1,4-dioxane, but these are controlled by quality manufacturing. It has low skin irritation and comedogenic ratings.
Who should be careful with PEG-90 Glyceryl Isostearate?
Individuals who strictly avoid all PEG-derived ingredients due to personal preference or environmental concerns
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.