active
Dimethicone
Silicone polymer providing slip, adhesion, and wear in colour cosmetics. Under pressure from the silicone-alternatives trend in clean beauty despite an excellent human safety record.
Benefits
- Slip and glide in eyeshadow and lip formulas
- Wear and adhesion improvement
- Semi-occlusive barrier protection
- Smooth application texture
- Long-wear performance
Example uses
- Eyeshadow sticks
- Silky primer formulas
- Long-wear lip products
- Foundation vehicles
- Skin prep serums
Mechanism of action
Polydimethylsiloxane forms a flexible, breathable film on the skin surface that reduces friction via its low surface energy. The Si-O-Si backbone and pendant methyl groups create a hydrophobic surface contributing wear longevity. Unlike petrolatum, the silicone film is semi-occlusive.
Clinical evidence · High
Extensively characterised. CIR concluded safe; SCCS confirmed safety. No skin mechanisms beyond physical.
Effective concentration range
2–20% in colour cosmetics
Formulation notes
Functions in anhydrous or low-water colour cosmetics. Immiscible with water unless specifically emulsified. Forms flexible silicone film on skin surface.
Watchouts
Non-biodegradable — environmental persistence concern in rinse-off products. Banned in many clean-beauty brand standards on environmental grounds despite strong human safety profile.
Controversies & overclaims
Clean-beauty exclusion of dimethicone is primarily driven by environmental persistence concerns, not human safety. This distinction is rarely made clearly in consumer-facing communications.
Market positioning
Marketed as smooth application and long-wear ingredient. Accurate. Clean beauty silicone-free framing prioritises environmental positioning over safety-based rationale.
Comedogenicity
1 / 5
Sensitisation risk
Low
INCI & aliases
Dimethicone
polydimethylsiloxane · PDMS · dimethylpolysiloxane
Clean beauty perception
Contested in clean beauty. Excellent human safety profile but environmental persistence drives exclusion. Clean-beauty movement has positioned silicones as problematic despite limited evidence of skin harm at cosmetic use.
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