active
Alumina
Used as a mechanical exfoliant in physical scrubs and professional-grade resurfacing products. Alumina microcrystals are the active medium in microdermabrasion devices.
Benefits
- Mechanical exfoliation — removes corneocytes via physical abrasion
- Smooths surface texture
- Chemically inert
- Uniform particle geometry allows controlled abrasion
- No bacterial contamination risk unlike organic scrubs
Example uses
- Physical face exfoliating scrubs
- Microdermabrasion creams
- Body buffs
- Foot scrubs
- Resurfacing masks
Mechanism of action
Functions purely via mechanical abrasion — hard particle surfaces create frictional shear stress on the stratum corneum during application, physically detaching corneocytes. No enzymatic, chemical, or receptor-mediated mechanism.
Clinical evidence · Moderate
Well-established in professional microdermabrasion literature with multiple RCTs. Topical scrub data largely non-comparative.
Effective concentration range
2–15% in scrub formulations
Formulation notes
Particle size critical — cosmetic grade typically 50–150 microns. Does not dissolve in water; requires thickener to maintain suspension.
Watchouts
Micro-laceration risk with over-use or aggressive pressure. Not appropriate for active acne, rosacea, or sensitised skin.
Controversies & overclaims
Physical scrubs broadly criticised for micro-laceration risk.
Market positioning
Sold as professional-grade resurfacing active. Professional framing misleading at home-scrub concentrations.
Comedogenicity
0 / 5
Sensitisation risk
Low
INCI & aliases
Alumina
aluminum oxide · corundum · Al2O3
Clean beauty perception
Neutral to mildly negative in clean-beauty. Largely replaced by enzyme exfoliants and AHAs in clean-positioned ranges.
Graph relationships
Timeline