Ingredient review
Undecylcrylene Dimethicone
INCI: UNDECYLCRYLENE DIMETHICONE
A silicone film-former that helps products stay put and resist water, but offers no active skincare benefit.
In plain English
Undecylcrylene Dimethicone is a synthetic silicone ingredient that creates a thin, flexible film on the skin. This film helps other ingredients—like sunscreen filters or makeup pigments—stay in place longer and resist water, sweat, and rubbing. It's commonly found in sunscreens and long-wear makeup. While it's generally safe and non-irritating, it doesn't moisturize or treat skin; it's purely a performance enhancer.
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
Undecylcrylene Dimethicone 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 Undecylcrylene Dimethicone.
- 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 silicone polymer (a type of synthetic silicone) that forms a water-resistant film on the skin or hair.
How it works
When applied, the silicone molecules link together to form a continuous, flexible layer. This layer physically blocks water from reaching the underlying product and helps pigments or active ingredients adhere to the skin for longer.
Pros
Boosts wear time
Creates a durable film that helps makeup and sunscreen stay on longer, even in water or humidity.
Low irritation risk
Rarely causes stinging or redness, making it suitable for sensitive skin types.
Cons and cautions
No active skincare benefit
Unlike humectants or antioxidants, this ingredient does not hydrate, soothe, or repair the skin.
Can feel heavy
On very oily or acne-prone skin, the film may feel slightly occlusive or contribute to a tacky finish.
Best for
- Anyone wanting longer-lasting sunscreen or makeup
- People who swim, sweat, or live in humid climates
Use caution if
- Those who prefer silicone-free or minimalist ingredient lists
Usage tips
Safety summary
Undecylcrylene Dimethicone is considered safe for topical use at typical cosmetic concentrations. It has a low irritation and comedogenic profile. However, because it is a film-former, thorough removal is recommended to avoid buildup.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have found similar silicone film-formers to be safe. Specific studies on Undecylcrylene Dimethicone are limited, but its chemical class is well-tolerated.
Common label clues
- Typical concentration
- 1–10%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU, and many other regions. No specific concentration limits are set, but typical use is under 10%.
- Common uses
- Sunscreens, Long-wear foundations, Water-resistant makeup, Eye makeup
- Environmental note
- As a silicone, it may not biodegrade quickly. Some manufacturers are exploring bio-based alternatives, but this is still a synthetic polymer.
Good to know
- This ingredient is often combined with other silicones like Dimethicone for a smoother feel.
- It is not considered comedogenic, but if you are prone to clogged pores, patch test first.
Common questions
What is Undecylcrylene Dimethicone in beauty products?
Undecylcrylene Dimethicone is a synthetic silicone ingredient that creates a thin, flexible film on the skin. This film helps other ingredients—like sunscreen filters or makeup pigments—stay in place longer and resist water, sweat, and rubbing. It's commonly found in sunscreens and long-wear makeup. While it's generally safe and non-irritating, it doesn't moisturize or treat skin; it's purely a performance enhancer.
What does Undecylcrylene Dimethicone do in a beauty product?
When applied, the silicone molecules link together to form a continuous, flexible layer. This layer physically blocks water from reaching the underlying product and helps pigments or active ingredients adhere to the skin for longer.
Is Undecylcrylene Dimethicone safe for most people?
Undecylcrylene Dimethicone is considered safe for topical use at typical cosmetic concentrations. It has a low irritation and comedogenic profile. However, because it is a film-former, thorough removal is recommended to avoid buildup.
Who should be careful with Undecylcrylene Dimethicone?
Those who prefer silicone-free or minimalist ingredient lists
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.