Zinc oxide vs titanium dioxide: Which is better?

What is the difference?

UVA contributes to premature skin ageing and can pass through window glass. UVB is the main cause of sunburn; overexposure to either can contribute to skin cancer. Zinc oxide's wider UVA coverage explains its advantage, but the finished formula matters too. Particle size and the combination of filters affect protection, so two products with the same headline mineral need not perform identically.12

Which should you choose?

Choose zinc oxide if you want broader UVA coverage from a single mineral filter. A formula combining zinc oxide and titanium dioxide is also a sensible option because their protection profiles complement each other. Do not reject a titanium dioxide sunscreen solely because of its mineral: check the finished product's broad spectrum claim, SPF and water resistance. The label's protection claims are more useful than declaring an ingredient champion, a competition neither mineral entered.14

For sensitive skin, look for a sunscreen labelled "sensitive skin" and avoid fragrance, parabens and oxybenzone. If sunscreen stings or burns, or you have rosacea, choose one whose sunscreen actives are only zinc oxide, titanium dioxide or both, and avoid fragrance. For oily or acne prone skin, look for "noncomedogenic" or "won't clog pores." For dry skin, look for "moisturizing" or "dry skin." These choices concern the whole formula, not just which mineral appears first.4

Which leaves less white cast?

Both minerals can leave white residue. Smaller mineral particles improve application and reduce that residue, so the mineral name alone is not enough to choose the better looking sunscreen. Tinted sunscreens containing iron oxide also help protect against visible light, which can worsen dark spots, particularly in darker skin tones.234

Are both minerals safe?

Both zinc oxide and titanium dioxide are included in the FDA's proposed category of sunscreen ingredients generally recognized as safe and effective. For nanoparticles, the established benefits of sun protection outweigh theoretical risks. European safety assessments consider specified nano titanium dioxide formulations safe for application to healthy, intact or sunburnt skin, at concentrations up to 25%. That is a skin application assessment, not permission to inhale sunscreen: avoid breathing in sprays and never spray them around the face or mouth.2356

How do you use either sunscreen?

1. 1Apply sunscreen every day you will be outdoors, covering skin not protected by clothing.
2. 2Apply to dry skin 15 minutes before going outside. Most adults need about one ounce for exposed skin; use at least one teaspoon for the face.
3. 3Cover easily missed areas, including your ears, neck, tops of your feet and exposed scalp.
4. 4Reapply approximately every two hours outdoors and after swimming or sweating. Water resistant labels specify 40 or 80 minutes of protection during swimming or sweating; follow the bottle's directions.
5. 5Use shade and protective clothing as well. For babies under six months, prioritize shade and clothing and ask a doctor before applying sunscreen.