Ingredient review
PEG-5 Hydrogenated Castor Oil Triisostearate
INCI: PEG-5 HYDROGENATED CASTOR OIL TRIISOSTEARATE
A gentle emulsifier that helps mix water and oil in your products, but it's processed with PEGs, which some people prefer to avoid.
In plain English
This ingredient is a helper that allows water and oil to blend together in your cleanser or moisturizer, so the product stays smooth and doesn't separate. It's made from castor oil that has been chemically modified with PEG (polyethylene glycol) and fatty acids. In your skincare, it works as an emulsifier and mild cleansing agent, helping to remove makeup and dirt without stripping your 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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-5 Hydrogenated Castor Oil 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-5 Hydrogenated Castor Oil 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 semi-synthetic compound created by reacting hydrogenated castor oil with PEG and isostearic acid. It belongs to a family of PEGylated castor oil derivatives used as emulsifiers and surfactants in cosmetics.
How it works
It reduces the surface tension between oil and water, allowing them to form a stable mixture (emulsion). In cleansers, it helps lift and rinse away oily impurities and makeup. In creams and lotions, it keeps the formula uniform and prevents separation.
Pros
Gentle cleanser
It removes makeup and sunscreen effectively without leaving skin feeling tight or stripped, making it suitable for daily use.
Formula stabilizer
It keeps oil-and-water mixtures from separating, so your lotion or cream stays smooth and consistent from first use to last.
Cons and cautions
PEG processing concerns
The PEG part of the molecule can be contaminated with ethylene oxide or 1,4-dioxane during manufacturing, though reputable brands use purified grades.
Not natural
Even though it starts from castor oil, the chemical processing makes it a semi-synthetic ingredient, which may not fit a 'natural' skincare routine.
Best for
- People with normal to dry skin looking for a gentle cleanser
- Anyone using oil-based makeup removers who wants a non-stripping formula
Use caution if
- Those who strictly avoid PEGs or semi-synthetic ingredients
- Individuals with known sensitivity to castor oil derivatives (rare)
Usage tips
Safety summary
Considered safe for use in cosmetics at typical concentrations. The main concern is potential contamination with ethylene oxide or 1,4-dioxane during manufacturing, but these are controlled by good manufacturing practices. Skin irritation and allergy are rare.
Research notes
The Cosmetic Ingredient Review (CIR) panel has reviewed PEGylated castor oil derivatives and concluded they are safe for cosmetic use when formulated to minimize impurities. No significant human or animal studies specifically on this ingredient are available, but its chemical class is well-studied.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and EU CosIng database. The Cosmetic Ingredient Review (CIR) panel has evaluated PEGylated castor oil derivatives and found them safe as used when properly purified.
- Common uses
- Cleansers, Makeup removers, Moisturizers, Sunscreens
- Environmental note
- PEG compounds are generally biodegradable, but their production involves petrochemical-derived ethylene oxide, which has a moderate environmental footprint.
Good to know
- PEG-5 Hydrogenated Castor Oil Triisostearate is often used in combination with other emulsifiers to create a gentle yet effective cleansing system.
- The number '5' in PEG-5 refers to the average number of ethylene oxide units, which affects its water solubility and mildness.
Common questions
What is PEG-5 Hydrogenated Castor Oil Triisostearate in beauty products?
This ingredient is a helper that allows water and oil to blend together in your cleanser or moisturizer, so the product stays smooth and doesn't separate. It's made from castor oil that has been chemically modified with PEG (polyethylene glycol) and fatty acids. In your skincare, it works as an emulsifier and mild cleansing agent, helping to remove makeup and dirt without stripping your skin.
What does PEG-5 Hydrogenated Castor Oil Triisostearate do in a beauty product?
It reduces the surface tension between oil and water, allowing them to form a stable mixture (emulsion). In cleansers, it helps lift and rinse away oily impurities and makeup. In creams and lotions, it keeps the formula uniform and prevents separation.
Is PEG-5 Hydrogenated Castor Oil Triisostearate safe for most people?
Considered safe for use in cosmetics at typical concentrations. The main concern is potential contamination with ethylene oxide or 1,4-dioxane during manufacturing, but these are controlled by good manufacturing practices. Skin irritation and allergy are rare.
Who should be careful with PEG-5 Hydrogenated Castor Oil Triisostearate?
Those who strictly avoid PEGs or semi-synthetic ingredients Individuals with known sensitivity to castor oil derivatives (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.