Zinc oxide
Zinc oxide is a mineral UV filter that FDA proposed in 2019 to class as generally recognised as safe and effective (GRASE) in sunscreens at up to 25%, because it stays on the surface of the skin.
Barrier creams containing it are widely used for nappy rash and have some support, but trials are small and mostly compare it with other products rather than with nothing, and for wounds one placebo-controlled trial found no difference in healing time. Sunscreen works only if you apply enough and reapply it, so FDA advises shade and clothing too.
At a glance
Last reviewed 10 October 2026What it's used for
Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.
| Use | Evidence | What the research shows |
|---|---|---|
| Sunscreen (broad-spectrum UV filter)Compare remedies for skin → | Moderate | In its 2019 proposed rule FDA proposed zinc oxide as Category I (GRASE) at up to 25%, saying it is insoluble and does not penetrate into or through human skin to any great extent, including nanoscale particles, and that zinc oxide reflects UVA to help give broad-spectrum protection. The rule was a proposal, and we could not open a current FDA page confirming the final status. Zinc-oxide-specific trials are not the basis: in the Nambour randomised trial (903 adults, 4.5 years), daily broad-spectrum sunscreen of unspecified filter cut skin ageing by 24% compared with discretionary use (relative odds 0.76, 95% CI 0.59 to 0.98). We rate this 3 on the regulatory assessment plus that sunscreen trial, not on a head-to-head trial of zinc oxide.1,7 |
| Nappy rash (barrier cream) | Limited | Evidence is small and mixed. In a randomised trial of 63 newborns in intensive care, a 40% zinc oxide and cod liver oil cream was no different from breast milk in days to clinical improvement (p = 0.294) but left lower lesion scores (p = 0.002). In 46 children with diarrhoea-related nappy rash, 5% dexpanthenol with zinc oxide ointment beat plain ointment base on skin water loss at day 3 but not on rash severity scores on days 1, 3 or 7. A literature review found ointments with zinc oxide or petrolatum had comparable effects on severity and said no study shows whether any practice prevents nappy rash. A 2026 meta-analysis of barrier preparations found the effect varied by product and had high heterogeneity (I2 79%); we do not quote its pooled figures, which look internally inconsistent in the abstract.2,4,3,5 |
| Wound care (topical) | Limited | In one randomised, double-blind trial of 64 people with open pilonidal wounds, 3% zinc oxide mesh did not significantly shorten healing time versus placebo mesh (median 54 versus 62 days, p = 0.32), though fewer people in the zinc group were prescribed antibiotics (3 versus 12, p = 0.005) and S. aureus was less common in wounds. The authors said larger trials are needed. FDA's review describes zinc oxide as used in non-sunscreen ointments, pastes and lotions for skin disorders for its protective, astringent and antiseptic properties, but that is a description of use, not evidence of benefit.6,1 |
How much
Ranges below are what studies used and what supplements commonly contain. They are not a recommendation for you. Start at the low end.
How people take it
Safety
Who should avoid
- Relying on sunscreen alone — FDA also advises shade, clothing and reapplying
- Open or weeping wounds — the trial was supervised; ask a clinician first
- Nappy rash that may be fungal — a barrier cream is not an antifungal
- Oral zinc for colds — a different compound, see the FAQ
Known interactions
Questions people ask
What are the benefits of zinc oxide for skin?
It acts as a mineral sunscreen filter, which FDA proposed in 2019 to class as GRASE at up to 25%, and as a barrier in nappy rash creams. The nappy rash evidence is small and mixed, and in the one placebo-controlled wound trial we found, zinc oxide did not significantly shorten healing time.
Is zinc oxide sunscreen safe, and what are the side effects?
FDA's 2019 review found zinc oxide, including nanoscale particles, does not penetrate into or through human skin to any great extent, and that any tiny absorption would not cause harm given the zinc already in the body.
A review of human sunscreen studies noted that most particles stay on the surface but that conclusions on penetration into viable skin are mixed. We found no reliable source on rates of skin irritation, so we make no claim about that.
Does zinc oxide cream work for nappy rash?
Possibly, but not proven against doing nothing. A 40% zinc oxide cream left newborns with lower lesion scores than breast milk, and a literature review found zinc oxide and petrolatum ointments had comparable effects on severity. Trials are small and there is no clear evidence on whether creams prevent nappy rash.
Is this the zinc that helps with colds?
No. Zinc oxide is used on the skin. Zinc taken by mouth for colds, usually as lozenges or syrups of other zinc salts, is a separate question, tested in a 2024 Cochrane review of 34 trials; we do not rate it here.
Make it yourself
DIY guides that use zinc oxide, with quantities, safety notes and an honest word on what they do.
Sources (10)
- Regulator proposal US Food and Drug Administration. Sunscreen Drug Products for Over-the-Counter Human Use (proposed rule). Federal Register. 2019.
- Randomised controlled trial Gozen D, Caglar S, Bayraktar S, Atici F. Diaper dermatitis care of newborns human breast milk or barrier cream. J Clin Nurs. 2014.
- Review Blume-Peytavi U, Hauser M, Lünnemann L, et al. Prevention of diaper dermatitis in infants--a literature review. Pediatr Dermatol. 2014.
- Randomised controlled trial Wananukul S, Limpongsanuruk W, Singalavanija S, Wisuthsarewong W. Comparison of dexpanthenol and zinc oxide ointment with ointment base in the treatment of irritant diaper dermatitis from diarrhea: a multicenter study. J Med Assoc Thai. 2006.
- Systematic review and meta-analysis Alkhamis ZZ, Bhagchandani M, Idris M, et al. Clinical Effectiveness of Barrier Preparations in the Management of Diaper Dermatitis: A Systematic Review and Meta-Analysis. Cureus. 2026.
- Randomised controlled trial Agren MS, Ostenfeld U, Kallehave F, et al. A randomized, double-blind, placebo-controlled multicenter trial evaluating topical zinc oxide for acute open wounds following pilonidal disease excision. Wound Repair Regen. 2006.
- Randomised controlled trial Hughes MC, Williams GM, Baker P, Green AC. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med. 2013.
- Systematic review Nault D, Machingo TA, Shipper AG, et al. Zinc for prevention and treatment of the common cold. Cochrane Database Syst Rev. 2024.
- Review Gulson B, McCall MJ, Bowman DM, Pinheiro T. A review of critical factors for assessing the dermal absorption of metal oxide nanoparticles from sunscreens applied to humans, and a research strategy to address current deficiencies. Arch Toxicol. 2015.
- Regulator guidance US Food and Drug Administration. Sunscreen: How to Help Protect Your Skin from the Sun. Understanding Over-the-Counter Medicines.
Last reviewed 10 October 2026 · Next review April 2027 · How we rate evidence
Reader notes
Experiences and questions from readers, read by an editor before they appear. They are personal accounts, not evidence, and are not medical advice.