She continues, “Reapplication helps restore more even coverage and maintain consistent UV protection throughout the day, reducing the risk of sunburn, premature aging, discoloration, and skin cancer. While mineral sunscreens are usually removed primarily through rubbing and physical wear, chemical sunscreens may also become less effective over time with continued UV exposure.”

What should we look for when choosing a base sunscreen?

“Choosing a sunscreen is very personal,” Dr. Kobets says, and ultimately “the best sunscreen is the one you’ll actually enjoy wearing and apply consistently.”

When looking for an everyday sunscreen, though, there are a few things that should be top priorities—and Dr. Shokeen has given us a quick, easy checklist: “Broad spectrum, SPF 30+, water-resistant if you’re active.”

Dr. Kobets cosigns broad-spectrum SPF 30 to 50, and tends to favor mineral sunscreens with zinc oxide and titanium dioxide: “They’re effective, well-tolerated, and provide complementary protection across the UV spectrum, with many newer formulations offering little to no white cast and a variety of tint options,” she says.

“Mineral sunscreens work by creating a protective layer on the skin that reflects, scatters, and absorbs UV radiation,” she explains further. “Zinc oxide provides excellent UVA coverage, while titanium dioxide is particularly effective in the UVB range. Many newer mineral sunscreens combine both ingredients for broad-spectrum protection, although zinc oxide-only formulas can also be an excellent option. Mineral sunscreens also begin working immediately after application because they sit on the skin’s surface rather than needing time to absorb.”

Dr. Kobets notes, too, that mineral sunscreens are often better tolerated by those with skin sensitivities, such as eczema, rosacea, and dermatitis.

Choosing a sufficient SPF is key, but it’s also crucial not to feel a false sense of security just because you select a higher number. “It’s important to remember that SPF is not a measure of how long you can stay in the sun; it reflects the level of UVB protection provided,” Dr. Kobets explains. “For example, SPF 30 blocks about 97% of UVB rays. In real life, reapplication is often more important than choosing between SPF 30 and SPF 50 because protection decreases as sunscreen wears off throughout the day. Newer sunscreens also provide PA++++ information for UVA protection and, ideally, your sunscreen should have both UVB and UVA protection.”