In theory, sunscreen with super-high SPF should give you the best protection against damaging UV radiation. But in practice, it may not work that way. In fact, some experts say using super-high-SPF sunscreens could lead to more UV exposure — upping your risk for both burns and skin cancer.
Experts say sunscreens with an SPF higher than 50 aren't worth buying. They only offer marginally better protection. They might also encourage you to stay out in the sun longer. Instead, choose an SPF between 15 and 50, apply liberally, and reapply often.
Under ideal conditions (like in a laboratory), a sunscreen with higher SPF protection and broad-spectrum coverage offers more protection against sunburn, UVA damage and DNA damage than comparable products with lower SPF values.
The SPF rating only refers to UVB rays. An SPF 15 sunscreen blocks 93% of UVB radiation, and SPF 30 blocks 97%. After that, the difference in protection is small. SPF 50 blocks 98%, and SPF 100 stops 99% of UVB rays from reaching your skin.
Protection isn't much better than low-SPF sunscreens
Building off of our last point, SPF 100 blocks about 99% of UVB radiation while SPF 50 blocks around 98%. Meaning that despite having twice as much SPF, it's only 1% more effective. There's not as much of a difference in protection as you'd think!
A sunscreen with SPF 30 will protect you from around 96.7% of UVB rays, whereas an SPF of 50 means protection from about 98% of UVB rays. Anything beyond SPF 50 makes very little difference in terms of risk of sun damage, and no sunscreens offer 100% protection from UVB rays.
The difference between a SPF 40 is you block out 97.5% of UVB radiation and SPF 50 blocks 98%. This is a very small difference for the cost of purchasing a SPF 50. More important than using a super high SPF is using enough sunscreen.
Sunburn protection that is only marginally better.
Properly applied SPF 50 sunscreen blocks 98 percent of UVB rays; SPF 100 blocks 99 percent. When used correctly, sunscreen with SPF values between 30 and 50 offers adequate sunburn protection, even for people most sensitive to sunburn.
Should you use SPF 100? Experts unequivocally say no. "The benefit is that it affords us about 1 percent more coverage from the UVB burning rays than an SPF of 50," says Ciraldo. "But the risk is not worth it."
An SPF also means that a certain percentage of skin-aging UVB rays are still allowed to penetrate the skin. According to the Skin Cancer Foundation , 3 percent of UVB rays can enter your skin with SPF 30, and 2 percent with SPF 50. This is also how you can still get tan while wearing sunscreen.
“Properly applied SPF 15 blocks 93 percent of UVB rays; SPF 30 blocks 97 percent of UVB rays; SPF 50 blocks 98 percent of UVB rays; and SPF 100 blocks 99 percent of UVB rays.” And while the difference in level of protection between SPF 30 and SPF 100 is only 2 percent, Dr.
Who Needs Sunscreen? Every child needs sun protection. The American Academy of Dermatology (AAD) recommends that all kids — regardless of their skin tone — wear sunscreen with an SPF of 30 or higher.
Sunscreen SPF and Skin Protection
For best protection, experts recommend using a minimum SPF sunscreen of 15, applying the proper amount (2mg/cm2 of skin, or about one ounce for full body coverage), and reapplying every 2 hours. Most people under-apply sunscreens, using ¼ to ½ the amount required.
The two-finger method is an easy way for you to measure how much sunscreen to apply to your face. To try this technique, simply squeeze the product in two separate lines on your pointer and middle finger. “For maximum coverage, the sunscreen protection factor has to be SPF 30 and above," Emaleku says.
Dermatologists recommend using an SPF of at least 30, which Adarsh Vijay Mudgil, MD, a dermatologist practicing in New York, calls "the magic number". SPF 15 blocks about 93 percent of UVB rays, while SPF 30 blocks about 97 percent of UVB rays. The ADA recommends an SPF of 30 or higher.
Put another way, if your unprotected skin would take ten minutes to show signs of burning, then properly applying SPF 30 sunscreen would slow the rate of burning to the point where it would take 30 times longer, or 300 minutes in total. SPF 15 would take 150 minutes, while SPF 50, 500 minutes.
SPF30 sunscreen with UVA rating of 4-5 stars is considered a good standard of sun protection. Sunscreens with really high SPFs, such as SPF 75 or SPF 100, do not offer significantly greater protection than SPF 30 and mislead people into thinking they have more protection than they actually do.
SPF works by extending your skin's natural defenses against the sun's rays. For example, an SPF of 15 provides about 15 times more protection than just your normal skin without sunscreen. An SPF of 50, then, would provide 50 times more protection than skin without sunscreen.
"SPF 15 protects against 93 percent of UVB rays, SPF 30 protects against 97 percent, and SPF 50 is about 98 percent," says Sejal Shah, a dermatologist in New York City. In other words, you get double the sun exposure when you opt for SPF 15 instead of SPF 30.
You'll want to use about . 04 ounces of sunscreen on your face, which equates to the size of a nickel or 1/4 to 1/3 of a teaspoon. Don't forget your neck, area behind your ears, temples, or hairline.
In theory, sunscreen with super-high SPF should give you the best protection against damaging UV radiation. But in practice, it may not work that way. In fact, some experts say using super-high-SPF sunscreens could lead to more UV exposure — upping your risk for both burns and skin cancer.
Key takeaways: Ultraviolet light from the sun can increase your risk of skin cancer and skin aging. Many safe and effective sunscreens are available, and it's important to use them the right way. Using sunscreen every day — no matter where you live or what color your skin — can protect you from sun damage.