Ingredient review
PEG-15 Hydrogenated Castor Oil Triisostearate
INCI: PEG-15 Hydrogenated Castor Oil Triisostearate
A gentle emulsifier that helps mix water and oil in cosmetics, with a low risk of irritation.
In plain English
This ingredient is a helper that keeps oil and water from separating in your lotions and creams. It's made by adding a small amount of PEG (a safe, water-loving molecule) to hydrogenated castor oil, which is a solid form of castor oil. The result is a mild emulsifier that creates a smooth, stable texture without being harsh 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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-15 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-15 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 emulsifier created by reacting hydrogenated castor oil with ethylene oxide (PEG) and isostearic acid. It belongs to the PEGylated castor oil family, known for their gentle cleansing and emulsifying properties.
How it works
Its molecular structure has both water-loving (PEG) and oil-loving (castor oil) parts, allowing it to bridge oil and water phases. When mixed, it reduces surface tension so tiny oil droplets can disperse evenly in water, creating a stable, creamy emulsion that doesn't separate.
Pros
Gentle on skin
Unlike some harsher emulsifiers, PEG-15 Hydrogenated Castor Oil Triisostearate has a low irritation risk, making it suitable for sensitive skin types and daily use.
Improves product feel
It helps create a smooth, creamy texture that spreads easily and feels luxurious on the skin, enhancing the user experience of creams and foundations.
Cons and cautions
Manufacturing impurities concern
As a PEG derivative, it may contain trace amounts of ethylene oxide or 1,4-dioxane, though cosmetic-grade ingredients are purified to safe levels set by regulators.
Not fully natural
Despite being derived from castor oil, the PEG modification makes it semi-synthetic, which may not appeal to those seeking 100% natural or biodegradable ingredients.
Best for
- Anyone using water-and-oil blend products like moisturizers or foundations
- People with normal to dry skin who want a stable, non-irritating formula
Use caution if
- Those with known allergies to castor oil derivatives (rare)
Usage tips
Safety summary
PEG-15 Hydrogenated Castor Oil Triisostearate is considered safe for cosmetic use at typical concentrations. The main concern is potential trace impurities from PEG production, but these are tightly controlled by regulations. It has low skin irritation and comedogenic risk, making it a safe choice for most people.
Research notes
Research on PEGylated castor oils shows they are effective, low-irritation emulsifiers. The Cosmetic Ingredient Review (CIR) has reviewed similar ingredients and concluded they are safe when formulated to limit impurities. No significant safety issues have been reported in published studies.
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 oils and found them safe as used in cosmetics, with restrictions on 1,4-dioxane levels.
- Common uses
- Foundations, Lipsticks, Creams, Sunscreens
- Environmental note
- PEG compounds can be slow to biodegrade in aquatic environments. However, the low concentrations used in rinse-off products minimize environmental impact. Some manufacturers are exploring greener alternatives.
Good to know
- PEG-15 indicates 15 ethylene oxide units, which balances water solubility and mildness
- Hydrogenated castor oil is a solid wax, so this ingredient helps create thicker, more stable creams
- Commonly found in color cosmetics like lipsticks and foundations for its smooth application
Common questions
What is PEG-15 Hydrogenated Castor Oil Triisostearate in beauty products?
This ingredient is a helper that keeps oil and water from separating in your lotions and creams. It's made by adding a small amount of PEG (a safe, water-loving molecule) to hydrogenated castor oil, which is a solid form of castor oil. The result is a mild emulsifier that creates a smooth, stable texture without being harsh on skin.
What does PEG-15 Hydrogenated Castor Oil Triisostearate do in a beauty product?
Its molecular structure has both water-loving (PEG) and oil-loving (castor oil) parts, allowing it to bridge oil and water phases. When mixed, it reduces surface tension so tiny oil droplets can disperse evenly in water, creating a stable, creamy emulsion that doesn't separate.
Is PEG-15 Hydrogenated Castor Oil Triisostearate safe for most people?
PEG-15 Hydrogenated Castor Oil Triisostearate is considered safe for cosmetic use at typical concentrations. The main concern is potential trace impurities from PEG production, but these are tightly controlled by regulations. It has low skin irritation and comedogenic risk, making it a safe choice for most people.
Who should be careful with PEG-15 Hydrogenated Castor Oil Triisostearate?
Those with known allergies 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.