Smarter: You Asked Us Sunscreen Questions. Here Are Our Answers.

1. Does sunscreen minimize tanning?
Tanning is triggered by the sun’s ultraviolet A (UVA) rays, and it’s your skin’s way of telling you that it’s suffering from sun damage. Any broad-spectrum sunscreen, which protects against the sun’s UVA and UVB rays, will minimize tanning. However, if you don’t consistently use enough sunscreen, you may still notice a tan. 

And if you’re in the sun a lot, over time you may get tanned even if you diligently apply and reapply because no sunscreen blocks 100 percent of the sun’s UV rays, says dermatologist Mona Gohara, MD, an associate clinical professor at Yale School of Medicine.

2. Does it help protect against melasma?
Melasma is a condition where dark patches appear on the skin, usually on the face. It can be worsened by UVA and visible light exposure, and “you don’t have a chance in heck of treating melasma if you don’t have a sunscreen that you’re using with regularity,” Gohara says. 

However, most sunscreens don’t shield against visible light, such as the glow from your computer screen or the sunlight you can see. So for protection, your best option may be a tinted broad-spectrum sunscreen containing iron oxide, because some evidence suggests the tint helps protect against visible light, Gohara says. And in general, mineral sunscreens might be a better choice than chemical sunscreens against melasma.

3. Does sunscreen lead to vitamin D deficiency?
No, studies have shown that the regular use of sunscreen is unlikely to cause vitamin D deficiency, says DiAnne Davis, MD, a board-certified dermatologist from Dallas. Because the amount of vitamin D a person receives from the sun is inconsistent and sun exposure increases the risk of skin cancer, the American Academy of Dermatology recommends getting vitamin D from a healthy diet of foods rich in vitamin D, food and beverages that are fortified with vitamin D, and/or vitamin D supplements. 

4. What SPF do I need?
A broad-spectrum sunscreen with a minimum of SPF 30 is recommended, says Trisha Calvo, a CR deputy editor who has written dozens of articles on sunscreens in the last eight years. But going for a higher SPF is a good move because in reality most people don’t use the right amount of sunscreen and reapply less frequently than recommended, says Ivy Lee, MD, board-certified dermatologist and Fellow of the American Academy of Dermatology.

To apply sunscreen correctly, make sure you use an ounce (a shot glass-full) to cover your entire body and reapply it every 2 hours.

5. If you applied sunscreen in the morning and stay indoors, do you still need to reapply it in the afternoon if you’re going out briefly, like going to your car and walking to the store?
Even if you’ve applied an adequate amount of sunscreen in the morning, it’s still recommended that you reapply sunscreen when you next go out if it’s been longer than 2 hours since you put sunscreen on, because it might rub off, Trisha says. You also might be outside in the sun longer than you think.

Another thing to note is that sun damage is accumulative, and your 5-minute outings here and there can add up to a lot of cumulative sun exposure over a longer course of time.

6. Are some European sunscreens more effective than American sunscreens?
There are a few European sunscreens that have more effective UVA blockers than their American counterparts. No new sunscreen filters have been approved by the Food and Drug Administration (FDA) since the 1990s, but there are still many existing sunscreen options in the U.S. that are effective. UVA protection is one of the things we test for when CR tests sunscreens, and you can check out our ratings for sunscreens that offer the best UVA protection (available for CR members).

7. I don’t really like sunscreens with strong fragrances. Do you have recommendations for sunscreens that are fragrance-free?
Among our top-rated sunscreens, La Roche-Posay Anthelios Melt-In Milk Lotion SPF 60 (Amazon, Target, and Walgreens) is fragrance-free and has a slight plasticky scent similar to a beach ball. From our testing, we’ve found that products marketed as no fragrance don’t always mean no odor and that many have a slight wet-clay or plastic beach ball scent.

And if you’re wondering what other sunscreens will give you top-notch protection against the sun’s rays, check out our review of the best sunscreens of the year.

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