Taking a stroll down the sunscreen aisle at your local pharmacy is always pretty confusing. SPF 30 or 45? Waterproof or water-resistant? Lotion or spray? But the most perplexing choice is between mineral sunscreen and those that are chemical-based. So we consulted two dermatologists to walk us through the pros and cons of each.
Also called physical sunscreens or "natural" sunscreens, these rely on minerals like zinc oxide and titanium dioxide that sit on the skin to deflect UV rays before UV radiation can penetrate the skin.
“I always prefer mineral sunscreens,” says dermatologist Caren Campbell MD, FAAD. “They protect against a broader spectrum of rays and offer sun protection immediately upon application. They provide a physical barrier from the sun’s harmful rays, meaning they reflect light rather than absorbing light which helps prevent heating of the skin and affords better sun protection.”
Other pros include being less allergenic. “Patients with sensitive skin should always err on the side of using mineral sunscreens, since zinc and titanium are the two main ingredients,” says Dr. Campbell.
Before you buy, however, be aware of the cons associated with mineral sunscreen. They include a thick consistency that can be hard to spread, and a white, pasty finish that can be difficult for those with darker skin tones, says Dr. Jenny Liu, assistant professor of Dermatology at the University of Minnesota.
Mineral sunscreens may rub off more easily than chemicals ones, especially when you’re swimming or sweating, and are difficult to wear under makeup.
That may be changing, says Dr. Liu, since “more microionized mineral sunscreens that are more cosmetically elegant are now available on the market.”
These formulas rely on — you guessed it — chemical compounds with ingredients like oxybenzone and octinoxate to convert UV radiation to heat which is then released from the body.
If you choose to use a chemical-based sunscreen, says Dr. Liu, you may find them to be “more cosmetically elegant compared to mineral sunscreen.” They are also more resistant to sweat and last longer in water.
On the negative side, you need to wait 20 minutes after applying to be in the sun and they can be harsh on sensitive skin. The chemicals in these sunscreens may irritate or sting your eyes. When in direct UV light, you may need to reapply more often. What’s more, some studies show they can harm the environment and, since they are absorbed by the skin, may disrupt the endocrine system, says Dr. Campbell.
Whichever formula you choose, SPF 30 or higher and broad spectrum are a must. "Reapplication is required every two hours or if you sweat or swim," says Dr. Campbell. “I always remind patients to protect lips, ears and temples, which are higher risk areas for metastasis or the spread of skin cancers internally when they’ve formed on the skin.”