Summer sunscreen guide: Learn how to avoid common sunscreen mistakes

by Kaiser Permanente |
Person with surfboard looks at ocean

Spending quality time outdoors can be great for your health — from getting some much-needed vitamin D to relieving stress. But too much exposure to the sun comes with risks, too — like sunburn, skin damage, and over time, skin cancer.

Of course, sunscreen is a big part of protecting yourself, but there’s a lot of misinformation out there. To help you filter out the myths, here are some basic sun protection tips, straight from a dermatologist.

4 common sunscreen questions

What SPF should you use?

Many people think that SPF, or sun protection factor, represents how much time you can wear a product before applying it again. But that’s not true. SPF measures how much UV radiation a sunscreen can absorb before it stops working.1 Don’t worry, though — Sarah Adams, MD, FAAD, a dermatologist with Kaiser Permanente in Southern California, has a quick answer for picking the right SPF.

“For me, the magic number is 30,” says Adams. SPF 30 blocks 97% of the UVB rays that cause sunburn.2 Anything above that only offers a little more protection — and nothing can block 100% of UVB rays.

Regardless of SPF, you should apply sunscreen at least every 2 hours, plus after going in the water. This goes for sunscreens that say they’re waterproof, too. “They’re not truly waterproof,” says Adams. “So, if you go in the water, you should reapply it.”

Do moisturizers with SPF work?

According to Adams, the SPF in a moisturizer can work just as well as SPF in sunscreen. But, you may not be applying enough product to get the coverage you need.

“It’s the same as with sunscreen,” Adams says. “If you just use a very small amount of sunscreen because you don’t like the way it feels or you think it’s greasy, then you’re not truly getting the SPF that’s on the bottle.”

Depending on your skin type, you may not want to keep applying moisturizer throughout the day, either. So it’s generally a good idea to have a separate sunscreen product if you’ll be spending much time outside.

“If you’re only going to and from your car or sitting by the window, then the SPF in your moisturizer is definitely better than nothing,” says Adams. “But, if you’re going to the beach and playing beach volleyball, then maybe you want more of a dedicated product.”

What’s the difference between chemical and mineral sunscreen?

Chemical sunscreen absorbs rays within your skin cells, like a filter. Mineral sunscreen blocks sun rays by sitting on top of your skin, and will contain active ingredients such as zinc oxide or titanium dioxide. A simple way to identify a chemical versus mineral sunscreen is by texture and appearance. Chemical sunscreens are usually transparent and less thick than mineral options. “Both protect you from sun damage,” says Adams, “and there’s no clear evidence that one is better for your health or more effective than the other.”

Some sunscreen chemicals can be harsh on the environment, though, particularly coral reefs. If you’re planning a beach vacation, you might want to consider an eco-friendlier mineral sunscreen. In fact, some places — like Hawaii — have outlawed chemical sunscreens to protect ocean life. Be sure to research your destination if you’re traveling, so you can pack accordingly.

For her own personal use, Adams likes a blend of minerals and chemicals. “I like that I’m getting some mineral protection but because it has a chemical mixed in, it’s a little bit thinner and lighter. But, it absolutely has to be broad-spectrum,” she says. That way, it protects against both UVA rays, which contribute to premature aging, and UVB rays, which cause burning — and can lead to cancer. Sunscreens that aren’t broad-spectrum most likely won’t offer protection against UVA rays.

When should you see a dermatologist about sun damage?

Small changes in your skin are normal over time, even if you apply sunscreen the right way. But it’s important to know what changes warrant a visit to a doctor. Adams says that new growths, bleeding, scabbing, and itching would all be signs to see a dermatologist.

Some preexisting factors could also justify more regular skin checks, like:

  • A high number of moles (100 or more, advises Adams)
  • Personal or family history of skin cancer
  • Fair skin
  • Blue eyes
  • Red hair

3 common sunscreen mistakes

It’s easy to make mistakes when using sunscreen. Here are some of the ones Adams sees most, and how to fix them.

Not applying it right

You should apply sunscreen evenly and thoroughly — more than you might think. Be extra aware of this when you’re using a spray sunscreen, says Adams. “Don’t step into the spray like you’re spraying perfume,” she explains. “You’re not going to get the density of sunscreen that you need to prevent burning that way — and you’re not putting it on evenly.”

Missing important spots

You may remember to apply sunscreen to your arms, legs, and face, but you could be missing some overlooked areas. “Your ears, neck, hands, and scalp are easy to burn,” says Adams, “and the top of your head is a common place for skin cancer to develop.” Long story short, sometimes you’re getting exposed to sun without even realizing it.

Using old or expired products

Whether you’re buying a new bottle or grabbing an old one at home, always check the expiration date. Direct sunlight can deactivate sunscreen too, so make sure to store yours in a cool place between uses so it lasts longer.

At the end of the day, find a product that’s a good balance of what’s effective and what you’ll use most often. “I always tell people,” Adams says, “the sunscreen that works is the sunscreen that you are actually going to put on your skin.”

Good health starts with prevention

From managing stress to quitting smoking, creating healthier habits can help prevent cancer. Learn more

“Sun Protection Factor,” U.S. Food & Drug Administration, accessed May 6, 2022.

“Sunscreen FAQs,” American Academy of Dermatology Association, accessed May 14, 2022.