Ingredient review
PEG-15 Glyceryl Triisostearate
INCI: PEG-15 GLYCERYL TRIISOSTEARATE
A reliable synthetic emulsifier that helps create stable, creamy formulas, but may not suit those avoiding PEG compounds.
In plain English
PEG-15 Glyceryl Triisostearate is a man-made ingredient that helps oil and water mix together in skincare products. It's part of a family of ingredients called PEGs (polyethylene glycols), which are widely used in cosmetics to create smooth, stable textures. This particular version is gentle on skin and helps moisturizers and cleansers feel creamy without being greasy.
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-15 Glyceryl Triisostearate 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-15 Glyceryl Triisostearate.
- 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 polymer derived from glycerin and isostearic acid, modified with polyethylene glycol (PEG) chains. It acts as a non-ionic surfactant and emulsifier.
How it works
It reduces the surface tension between oil and water, allowing them to blend into a stable emulsion. This prevents products from separating and gives them a smooth, uniform texture.
Pros
Effective emulsifier
Helps oil and water mix smoothly, giving products a consistent, creamy feel that doesn't separate over time.
Low irritation
Generally well-tolerated by most skin types, including sensitive skin, with a low risk of irritation or clogged pores.
Cons and cautions
Synthetic origin
Derived from petroleum-based materials, which may be a concern for those seeking natural or plant-based skincare.
Potential impurities
PEG compounds can sometimes contain trace impurities like ethylene oxide or 1,4-dioxane if not properly purified, though reputable brands ensure high-quality sourcing.
Best for
- People who use moisturizers, cleansers, or sunscreens and want a stable, non-greasy formula
- Those with normal to dry skin looking for a gentle emulsifier
Use caution if
- Individuals who prefer to avoid all synthetic or PEG-based ingredients
- Those with known sensitivity to PEG compounds (rare)
Usage tips
Safety summary
PEG-15 Glyceryl Triisostearate is considered safe for use in cosmetics at typical concentrations. The main concern is potential contamination with impurities during manufacturing, which is minimized by good manufacturing practices. It has low irritation and comedogenic potential.
Research notes
The Cosmetic Ingredient Review (CIR) panel has reviewed PEG compounds and concluded they are safe for use in cosmetics. No specific studies on PEG-15 Glyceryl Triisostearate alone were found, but it is grouped with similar PEG ethers and esters that have a strong safety record.
Common label clues
- Typical concentration
- 1-5%
- Regulatory status
- Approved for use in cosmetics by the FDA and EU CosIng database. The Cosmetic Ingredient Review (CIR) panel has deemed PEG compounds safe as used in cosmetics.
- Common uses
- Moisturizers, Cleansers, Sunscreens, Makeup removers
- Environmental note
- PEG compounds are generally biodegradable, but their production relies on fossil fuels. Some environmental groups prefer plant-based alternatives.
Good to know
- PEG numbers (like 15) refer to the length of the polymer chain, which affects how the ingredient behaves in water and oil.
- This ingredient is not typically listed as a main active but plays a key role in product stability.
Common questions
What is PEG-15 Glyceryl Triisostearate in beauty products?
PEG-15 Glyceryl Triisostearate is a man-made ingredient that helps oil and water mix together in skincare products. It's part of a family of ingredients called PEGs (polyethylene glycols), which are widely used in cosmetics to create smooth, stable textures. This particular version is gentle on skin and helps moisturizers and cleansers feel creamy without being greasy.
What does PEG-15 Glyceryl Triisostearate do in a beauty product?
It reduces the surface tension between oil and water, allowing them to blend into a stable emulsion. This prevents products from separating and gives them a smooth, uniform texture.
Is PEG-15 Glyceryl Triisostearate safe for most people?
PEG-15 Glyceryl Triisostearate is considered safe for use in cosmetics at typical concentrations. The main concern is potential contamination with impurities during manufacturing, which is minimized by good manufacturing practices. It has low irritation and comedogenic potential.
Who should be careful with PEG-15 Glyceryl Triisostearate?
Individuals who prefer to avoid all synthetic or PEG-based ingredients Those with known sensitivity to PEG compounds (rare)
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.