Sun protection has become a natural part of fun in the sun. Most of us throw a bottle of sunscreen into our beach bags and hiking packs before going out for the day, and for good reason. The American Cancer Society reminds us that sun exposure can significantly raise a person's risk of developing skin cancer, the most common type of cancer, affecting one in five people by the time they turn 70.

But as second nature as sunscreen has become, many people still aren’t exactly sure what kind to buy, how much to use, if they should pay attention to the expiration date and why some sunscreens have no expiration date. Read on to brush up on your SPF IQ with our 9 sunscreen tips for healthy skin.

Sunscreen really does expire.

Using sunscreen after the expiration date can be risky, as the product can lose its effectiveness over time. Check your sunscreen's expiration date, and make sure you use it before then. If there's no expiration date, it's because the product has been proven to be stable for at least three years. After that time, throw away any unused product and get yourself a new bottle.

Tip: Write the purchase month and year in permanent marker on sunscreen that has no expiration date. After all, who can remember what they bought three years ago?

SPF doesn’t refer to the number of minutes the sunscreen lasts.

SPF actually stands for sun protection factor, which indicates the percentage of UV ray defense. SPF is determined by a complex calculation. For example, SPF 30 protects against about 97% of UVB rays, while SPF 50 protects against about 98% of those rays.

Tip: While a higher SPF does give you more protection, you still need to reapply it every two hours, or more often if your body gets wet. Unfortunately, high SPF products can give people a false sense of security that could lead to burns, so no matter what SPF you're applying, make sure you reapply often.

You need more sunscreen than you think you do.

You should probably use more sunscreen than you think you need. Most people only use up to half of the recommended amount. For each use, aim to cover your whole body using about an ounce of sunscreen.

Tip: Imagine filling a shot glass with sunscreen to envision how much you should use for each application.

You need sunscreen when it's cloudy.

An overcast day doesn't mean that UV rays aren't getting through to the earth's surface. In fact, up to 80% of those rays can still reach your skin. Even so, the American Academy of Dermatology reports that about 4 in 5 Americans skip sunscreen when it's not sunny outside, which is a mistake because it leaves your skin vulnerable to sun exposure.

Tip: Always wear sunscreen outside, rain or shine.

All sunscreen is not the same.

Two sunscreens with the same SPF may not protect skin equally. Check the labels for these three important pieces of information:

  • Broad-spectrum (which protects against both UVA and UVB rays)
  • SPF of 30 or higher
  • Water-resistance (which means the sunscreen will stay active for up to 40 minutes of swimming)

Tip: Toss any sunscreen that doesn’t meet these standards, even if it hasn’t expired.

Sunscreen ingredients are undergoing testing, but you shouldn’t stop using it.

In the last couple of years, there has been a lot of attention on and research into the safety of ingredients found in “chemical sunscreens,” as reported by Prevention magazine. Chemical sunscreens absorb the sun’s rays like a sponge and tend to rub easily into the skin without leaving a white residue. In 2019, the FDA removed a majority of common sunscreen ingredients from its “Generally Recognized as Safe and Effective” or GRASE, list after it was found that several of these chemicals can be absorbed into the bloodstream.

While research is ongoing, the American Academy of Dermatology emphasizes that all approved sunscreen types on the market are still recommended and that none of them have been found to be unsafe. The academy encourages the use of both chemical and physical sunscreens to protect against the known dangers of skin cancer.

Tip: For extra peace of mind — especially for children and those with sensitive skin — look for sunscreen with zinc oxide or titanium dioxide. These two ingredients are the only ones currently listed as GRASE for use in sunscreen. They're found in "physical sunscreens" (also called “mineral sunscreens”) and protect against sun exposure by creating a physical barrier (typically a white residue) on the skin that reflects and disperses UV rays.

You can still get a tan when you use sunscreen.

Tanning after sun exposure is a sign of skin damage, which is why public health experts recommend regular sunscreen use. The UVA rays that lead to tanning also increase cancer risk, so if you want a tan, choose alternatives like self-tanners.

Tip: Avoid tanning beds, which have not been found to be safer and may be even more dangerous due to their consistently high intensity.

Sunscreen can reduce vitamin D intake.

While the regular use of sunscreen can reduce your vitamin D intake from the sun, there are things you can do to reduce your risk for a vitamin deficiency. The body uses sunlight to produce vitamin D, but many people can still get enough vitamin D from their diet or by taking supplements. Options like salmon, milk and fortified cereal are good choices that contain vitamin D.

Tip: Talk to your doctor if you have any concerns about vitamin deficiency.

Staying proactive about skin health

Along with covering your skin with protective clothing such as hats and long-sleeved shirts, using sunscreen regularly is one of the best things you can do to support your skin health. Remember that you should also be proactive about making appointments for skin-related screenings and checkups. Ask a dermatologist for a skin screening at least once a year — this routine appointment can help you get signs and symptoms checked out as early as possible.

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