Ingredient review
C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer
INCI: C30-45 ALKYL DIMETHICONE/POLYCYCLOHEXENE OXIDE CROSSPOLYMER
A silicone-based ingredient that improves product texture and wear, generally well-tolerated but not biodegradable.
In plain English
This is a type of silicone that forms a thin, flexible film on your skin. It helps makeup and skincare products glide on smoothly, feel silky, and last longer without feeling greasy. Think of it like a lightweight, breathable veil that gives a soft-focus finish.
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
C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer 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 C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer.
- 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 silicone polymer made by combining a long-chain alkyl dimethicone with a polycyclohexene oxide crosspolymer. It is a solid or semi-solid at room temperature and is used to modify the texture and feel of cosmetic products.
How it works
When applied, it spreads into a thin, even film that fills in fine lines and pores for a smoother appearance. It also helps other ingredients stay on the skin longer and reduces the transfer of makeup to clothing or masks.
Pros
Silky, smooth texture
Creates a velvety feel on skin that helps makeup apply evenly and reduces the appearance of fine lines and pores.
Long-lasting wear
Forms a flexible film that helps products stay in place longer and reduces transfer to clothes or masks.
Cons and cautions
Environmental persistence
As a silicone-based polymer, it is not readily biodegradable and may contribute to environmental accumulation over time.
Potential heaviness on oily skin
In high concentrations, it can feel slightly heavy or slippery on very oily skin types, though this is rare in typical formulations.
Best for
- Anyone who wants a smooth, primer-like finish from their moisturizer or sunscreen
- People with normal to dry skin looking for a silky texture without heavy oils
Use caution if
- Those who prefer entirely biodegradable or natural formulations
Usage tips
Safety summary
Generally recognized as safe for topical cosmetic use. It is non-irritating and non-comedogenic for most skin types. The main concern is environmental persistence rather than human safety.
Research notes
Safety data is based on the broader class of silicone polymers, which have a long history of safe use in cosmetics. Specific studies on this exact crosspolymer are limited, but no significant toxicity or irritation has been reported in standard tests.
Common label clues
- Typical concentration
- 1% to 10%
- Regulatory status
- Approved for use in cosmetics in the US, EU, and other major markets. No concentration restrictions are specified, but typical use is under 10%.
- Common uses
- Moisturizers, Primers, Sunscreens, Foundations
- Environmental note
- Silicone-based polymers like this one are not readily biodegradable. Some manufacturers are working on more eco-friendly alternatives, but this ingredient remains common due to its performance.
Good to know
- This ingredient is often found in 'primer' products and long-wear foundations.
- It is considered safe by major regulatory bodies when used in cosmetics at typical levels.
Common questions
What is C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer in beauty products?
This is a type of silicone that forms a thin, flexible film on your skin. It helps makeup and skincare products glide on smoothly, feel silky, and last longer without feeling greasy. Think of it like a lightweight, breathable veil that gives a soft-focus finish.
What does C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer do in a beauty product?
When applied, it spreads into a thin, even film that fills in fine lines and pores for a smoother appearance. It also helps other ingredients stay on the skin longer and reduces the transfer of makeup to clothing or masks.
Is C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer safe for most people?
Generally recognized as safe for topical cosmetic use. It is non-irritating and non-comedogenic for most skin types. The main concern is environmental persistence rather than human safety.
Who should be careful with C30-45 Alkyl Dimethicone/Polycyclohexene Oxide Crosspolymer?
Those who prefer entirely biodegradable or natural formulations
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.