Zinc Oxide

Zinc oxide is an inorganic mineral UV filter and skin protectant typically used at ~5–25% in barrier creams and sunscreens; it is generally non-stinging and well-tolerated even in eczema and post-procedure skin. Clinical and patch-test experience shows a low rate of irritant reactions, with most complaints related to dryness, occlusion, or product vehicle rather than zinc oxide itself. Because rare irritation can still occur in highly reactive or broken skin (especially with higher loads and friction), I rate it as very gentle rather than completely inert. Safety Notes: In commercial skincare, zinc oxide appears at very low levels (~0.1–1%) in soothing/barrier creams, anti-redness products, and some mineral-tinted moisturizers where it functions more as a skin protectant/opacifier than as the primary UV filter. The highest consumer-available concentrations are found in leave-on mineral sunscreens and sun sticks, where zinc oxide commonly reaches ~20–25% to achieve high SPF/broad-spectrum claims (within typical US/EU regulatory frameworks for OTC cosmetic/OTC-drug style sunscreens). Rinse-off cleansers may include zinc oxide, but usually at the low end due to wash-off and texture constraints, while the market maximum is dominated by leave-on sunscreen formats.