Zinc Oxide

Description

Zinc oxide is an inorganic (mineral) broad-spectrum UV filter that provides protection against both UVA and UVB radiation. It is one of only two FDA Category I sunscreen actives classified as GRASE (Generally Recognized as Safe and Effective), the other being titanium dioxide. Beyond photoprotection, zinc oxide has well-documented anti-inflammatory, antimicrobial, and wound-healing properties, making it particularly suitable for sensitive, acne-prone, and rosacea-affected skin. It is available in both micronized and non-nano forms to improve cosmetic elegance while maintaining safety.

Mechanism of Action

Zinc oxide protects against UV radiation primarily through reflection and scattering of UV photons, along with absorption of UV energy by zinc oxide particles. It provides broad-spectrum coverage from 290–380 nm, with particularly strong UVA protection compared to most organic filters. Upon skin application, zinc ions released from ZnO exert anti-inflammatory effects by inhibiting NF-κB signaling and reducing pro-inflammatory cytokines (IL-1α, IL-6, TNF-α). Antimicrobial activity is attributed to generation of reactive oxygen species on the particle surface and direct disruption of bacterial cell membranes. Zinc also supports wound healing by promoting keratinocyte migration and collagen synthesis.

Indications

• Broad-spectrum UV protection
• Sensitive skin sun protection
• Acne-prone skin sun protection
• Rosacea-prone skin sun protection
• Diaper dermatitis
• Minor wounds and skin irritation
• Anti-inflammatory skin protection

Available Concentrations

Side Effects

• White cast (especially in higher concentrations and darker skin tones)
• Dryness with prolonged use
• Rare contact dermatitis
• Potential comedogenicity at very high concentrations in some formulations

Pregnancy Category

FDA Category I sunscreen active (safe — minimal systemic absorption)

Found In

Cosmetics containing Zinc Oxide

Related Conditions