Ingredient review
PEG-15 Glyceryl Isostearate
INCI: PEG-15 Glyceryl Isostearate
A reliable synthetic emulsifier that helps create stable, creamy formulas, but may not suit those avoiding PEGs.
In plain English
PEG-15 Glyceryl Isostearate is a man-made ingredient that helps oil and water mix together in a product. Think of it as a bridge that keeps the formula from separating into layers. It is often used in lotions, creams, and cleansers to give them a smooth, even texture. The 'PEG' part refers to polyethylene glycol, a type of polymer that has been processed to be gentle on skin.
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 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-15 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
PEG-15 Glyceryl Isostearate is a synthetic emulsifier derived from glycerin and isostearic acid, modified with 15 units of polyethylene glycol (PEG). It belongs to a class of ingredients called PEG esters, which are widely used in cosmetics to stabilize mixtures of oil and water.
How it works
In a cosmetic product, PEG-15 Glyceryl Isostearate positions itself at the boundary between oil and water droplets. Its water-loving (hydrophilic) PEG chain pulls toward water, while its oil-loving (lipophilic) fatty acid tail pulls toward oil. This reduces surface tension and prevents the two phases from separating, resulting in a stable, homogeneous cream or lotion.
Pros
Effective emulsifier
Helps oil and water blend into a stable, creamy texture that feels smooth on the skin and doesn't separate over time.
Low irritation potential
Generally considered gentle and non-irritating for most skin types, making it suitable for daily-use products like moisturizers and cleansers.
Cons and cautions
Synthetic origin
Derived from petrochemicals, which may be a turn-off for those seeking natural or plant-based skincare ingredients.
Potential for impurities
PEG compounds can contain trace amounts of ethylene oxide or 1,4-dioxane if not properly purified, though reputable manufacturers follow strict safety standards.
Best for
- People who use conventional lotions, creams, or cleansers
- Those looking for stable, non-separating formulas
Use caution if
- Individuals who strictly avoid PEGs or synthetic ingredients
- Those with known sensitivity to PEG compounds (rare)
Usage tips
Safety summary
PEG-15 Glyceryl Isostearate is considered safe for use in cosmetics at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has evaluated PEG esters and found them safe when formulated to be non-irritating. The main safety concern is potential contamination with ethylene oxide or 1,4-dioxane, but these are tightly regulated and minimized in high-quality ingredients.
Research notes
Research on PEG esters supports their safety and efficacy as emulsifiers. Studies show they are generally non-irritating and non-sensitizing at low concentrations. The CIR panel has reviewed PEG compounds and concluded they are safe for cosmetic use when formulated properly. No significant human health risks have been identified from topical application.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission, with concentration limits typically set by good manufacturing practices.
- Common uses
- Cleansers, Moisturizers, Sunscreens, Makeup removers
- Environmental note
- PEG compounds are generally biodegradable, but their production relies on petrochemicals, which have a higher environmental footprint than some plant-derived alternatives.
Good to know
- PEG-15 Glyceryl Isostearate is often used in combination with other emulsifiers to create a balanced formula.
- The number '15' indicates the average number of ethylene glycol units, which affects how water-loving the molecule is.
Common questions
What is PEG-15 Glyceryl Isostearate in beauty products?
PEG-15 Glyceryl Isostearate is a man-made ingredient that helps oil and water mix together in a product. Think of it as a bridge that keeps the formula from separating into layers. It is often used in lotions, creams, and cleansers to give them a smooth, even texture. The 'PEG' part refers to polyethylene glycol, a type of polymer that has been processed to be gentle on skin.
What does PEG-15 Glyceryl Isostearate do in a beauty product?
In a cosmetic product, PEG-15 Glyceryl Isostearate positions itself at the boundary between oil and water droplets. Its water-loving (hydrophilic) PEG chain pulls toward water, while its oil-loving (lipophilic) fatty acid tail pulls toward oil. This reduces surface tension and prevents the two phases from separating, resulting in a stable, homogeneous cream or lotion.
Is PEG-15 Glyceryl Isostearate safe for most people?
PEG-15 Glyceryl Isostearate is considered safe for use in cosmetics at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has evaluated PEG esters and found them safe when formulated to be non-irritating. The main safety concern is potential contamination with ethylene oxide or 1,4-dioxane, but these are tightly regulated and minimized in high-quality ingredients.
Who should be careful with PEG-15 Glyceryl Isostearate?
Individuals who strictly avoid PEGs or synthetic 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.