The Truth About Sunscreen

We talked to a dermatologist to get the real facts on sun protection.


The photo above is the sunscreen aisle at CVS. A mess, right? What is the difference between UVB and UVA rays? Should I use SPF 4? 50? 100? How do we choose what is right for us? We asked Dr. Joseph Merola, a dermatologist at Brigham and Women’s Hospital and an instructor at Harvard Medical School, for some answers.

Pick a sunscreen you will use.  “First and foremost, people have to pick something that they like, because that means they will use it,” he says.

No more SPFs beyond 50, and none below 15. Did you see the recent Neutrogena commercial starring Jennifer Garner touting the SPF 100? So did we. “I think with regards to the SPF number, the FDA has changed the regulations quite a bit. We’re no longer going to be seeing SPFs beyond 50. It was supposed to happen last year over the summer, but I think some of the companies were a little delayed in making that happen. It gives kind of a false sense of security and it hasn’t been regulated,” Merola says. “Consumers won’t be seeing above 50 anymore. Also, with regard to the SPF number, we really should be doing a minimum of 15. Everyone should really forget about the 2, 4, 5, 10.”

It’s all about reapplying. “We recommend reapplying every two hours unless you’ve been sweating heavily or coming out of the pool or swimming, in which case you should apply more frequently,” he says.

Pick something that’s broad spectrum. “That means that it covers both UVA and UVB and offers protection from both. Most of the labels should say UVA and UVB broad spectrum protection. Now, the FDA is also regulating that. That’s new as of this year, the end of last year, that if it says broad spectrum, they have to prove that it really is broad spectrum,” Merola says.

UVA and UVB are both bad. “So historically we only would cover UVB, and UVB we used to think was the bad UV player, and that meant that it was the one that we associated with burns, and what we associated with skin cancer. In turns out that there’s increasingly evidence to support the idea that UVA is just as bad, if not worse,” Merola says. “It’s associated with skin cancer, it is associated with aging, and that’s another reason to use your sunscreen, is it’s associated with that leathery skin that you saw on grandma. UVA is really a big contributing factor to sun damage, and it goes deeper into the skin. It’s really affecting the collagen, it’s aging the collagen prematurely and also does increase our risk for certain types of skin cancer.”

You are not safe in your car, either. If you havent seen the image of the trucker and his skin from the sun (on one side of his body), Google it. “Here’s the other one key point about UVA that people forget: It is the kind of UV that comes right through the window glass, right through the windshield. So when you’re driving and you think you’re behind the glass and you’re protected, it’s actually the kind that’s coming right through and putting you at risk,” he says. “People in the US have more sun damage on the left side of their face because we drive in the left seat; people in the UK have all the sun damage and increase in cancer on the right side because they drive on the other side of the road. UV is coming right through the glass, and it’s not as though you can roll up the windows and you’re somehow protected, which some people think—even with tint. Tint helps, but it’s still not perfect.” And we are pretty sure tint is illegal in Mass., anyway.

Waterproof sunscreen does not exist. “[From now on] it’s only going to say water resistant. And that’s because really no sunscreen is waterproof; we always have to reapply. Some things are more water resistant and it’s better if you’re going to be sweating or in the pool, but you still have to remember to reapply,” Merola says.

The spray-on sunscreens don’t work. “The problem with spray-on sunscreens…we don’t generally recommend them. They are convenient, but there’s about three reasons why we don’t recommend them. People tend to not use them enough. So you really have to spray your arm or whatever it is, whatever area you’re covering, until it’s really wet and saturated, and then rub it on. Most people do not do that; they mist their skin, and that’s not sufficient. That’s number one. Number two, they are flammable, so don’t use them around the barbecue on the Fourth of July because people have caught on fire,” he says. “Number three, they’re not FDA approved for inhaling. So you have to be really careful to hold your breath when you use them [because] we don’t know how safe they are to inhale them. So for all those reasons, we don’t tend to really strongly recommend them. The mists, all those kinds of spray-ons. And there’s also a powder that actually is not FDA approved and should not be used.”

A white T-shirt is already SPF 4. “There are a lot of companies that sell very lightweight high SPF clothing that’s very helpful for people. The other thing is there’s actually a product called Rit Sun Guard that you can put into your laundry and increase the SPF of your clothes. It lasts four or five washes—that can be helpful for people. A typical white t-shirt has an SPF of 4 or 5, and if you put this in the wash it increases the SPF to about 30,” he says.

Chemical versus physical blocking sunscreens is a hot debate. “I’m not saying I agree with this concern, but there’s some concerns about the chemicals in the chemical-based sunscreens, which is most of them. So some people, if they’re worried about the health concerns in some of the newer literature that’s coming out that maybe, and it’s not proven, but maybe concerning around chemical sunscreens, then we strongly recommend physical blocker sunscreens. And those are usually the ones that contain zinc oxide or titanium dioxide; they’ll say things like sensitive skin on them. Inherently they’re automatically broad spectrum, and those are absolutely the only ones we want to use on children under six months,” Merola says.

Self tanner is just fine. “Self tanner, if you’re putting it on yourself, the kind you rub on, the ones you rub on yourself, totally safe. Nothing to worry about. In fact, some of them even have SPF included in it so you get a little bit of tan and sunscreen—great, we totally approve of those. The kind that we’re worried about and we’re not sure about their safety is the kind where you get a spray-on tan. That’s a whole other issue.”

People really forget a couple of major, important areas to put the sunscreen. “Earlobes—super important, don’t forget, especially guys. Lips—you need to get some kind of lip balm with SPF, the lower lip, in particular, is a high risk of skin cancer. And don’t forget the shades for your eyes,” Merola says.