Zinc Oxide

Evidence by route

About this ingredient

Zinc Oxide (ZnO) is a broad-spectrum mineral UV filter. Protects against UVA (320-400 nm) and UVB (290-320 nm), covering the entire UV spectrum. Unlike titanium dioxide, it also blocks UVA1 – the longest-wavelength UV responsible for photoageing and melasma flare-ups. Used in dermatology since the 1900s as a nappy-rash ointment. Mechanism. Works as a physical screen – reflects and scatters UV (~10% of effect) and absorbs most UV (~90% per new models). Contrary to the old view 'ZnO only reflects', modern studies confirmed the mixed mechanism (Cole 2015). Does not generate free radicals under UV (unlike nano-TiO2). Where applied. Sunscreens: ISDIN Mineral Brush Powder, La Roche-Posay Anthelios UVMune 400 Mineral, Avène Mineral Tinted Compact, Bioderma Photoderm Mineral, Eucerin Sun Mineral. Use levels: 5-25%. Also in nappy-rash products (Sudocrem, Mustela Vitamin Barrier Cream), zinc paste (Aleva, Lassar's paste), anti-irritation ointments. Evidence base. Mansfield 2016 systematic review confirmed ZnO efficacy as a UV filter at 10-25%. UVA1 (340-400 nm) protection exceeds most organic filters (except Tinosorb S and Mexoryl 400). For melasma, AAD 2024 recommends mineral sunscreens with ZnO as first-line. Safety. SCCS confirmed ZnO safety up to 25% in sunscreens. Nano-form ZnO (<100 nm) is safe in topical use on intact skin (Filipe 2009) but banned in sprays (theoretical inhalation risk). On damaged skin nano-particles may penetrate deeper – with wounds, acne papules, or right after procedures, the non-nano form is preferable. White cast controversy. Nano-ZnO (50-100 nm) gives less white cast than traditional (>200 nm) but with lower protection efficacy. Modern tinted mineral sunscreens with iron oxides mask the white cast and at the same time protect against visible light (HEV) and blue light. Pregnancy and lactation – preferred agent. AEMPS, AAD 2024 and WHO recommend ZnO as first-line UV filter in pregnant and breastfeeding women – zero systemic absorption, no endocrine effects, unlike oxybenzone and octinoxate. For gestational melasma it is a mandatory part of the protocol. Suited for. All skin types, especially sensitive, reactive, post-procedure, rosacea, perioral dermatitis, pregnancy and lactation. Suitable for children from 6 months.

Tolerability and safety

Explore by category

Combinations with other ingredients

Frequently asked questions