Table of Contents
Author, Fayne Frey, MD
Yes, we need them! The higher the SPF (Sun Protection Factor), the more sunburn protection the sunscreen provides. It’s that simple. SPF is the amount of energy (ultraviolet light) that is necessary to cause sunburn on protected skin (with sunscreen) in relation to the amount of energy required to cause sunburn on unprotected skin (without sunscreen.) So the higher the SPF, the more sunburn protection the product affords. A recent study found SPF 100 sunscreen prevents more sunburn than SPF 50.
“I Wear Sunscreen and Still Burn”
When patients complain sunscreen does not protect them from sunburn, I generally ask a few pointed questions to determine possible reasons. I often find these individuals use low SPF products because they heard somewhere any SPF level over 30 is a waste, a common misconception. In other cases, it is clear these well-meaning sunscreen users don’t apply enough to achieve the level of protection touted on the label.
The average adult requires approximately 1 ounce (a shot glass full) to adequately cover all exposed skin when in a bathing suit. Of course, a 200-pound individual needs a bit more, and a 100-pound person a bit less. Keep in mind that since no sunscreen maintains its SPF for more than 2 hours, reapplication is necessary throughout the day. Every two hours is a good rule of thumb, but lather up more frequently if you are swimming or excessively sweating. A sunscreen with a high SPF absolutely helps prevent sunburn if used as advised.
“I Don’t Need High SPF Sunscreen Because I Don’t Burn”
Some patients insist they do not need sunscreen because they don’t burn. Sorry, not true. You don’t have to burn to damage your skin.
Here’s why. The sun emits a wide spectrum of radiation energy (ultraviolet light), not all of which causes sunburn. Ninety-five percent of the radiation that reaches the earth’s surface is deep penetrating ultraviolet A (UVA) radiation. UVA rays get into the dermis, the skin’s thickest layer. Unprotected exposure can lead to premature skin aging, wrinkling and suppression of the skin’s immune system. Because UVA rays don’t cause sunburn, you may not be aware to what extent the sun is harming your skin. Do yourself a favor and wear the sunscreen.
“I’m Confused About UVA vs. UVB Ultraviolet Rays. Why Do I Care?”
You need to care. First of all, SPF refers only to UVB rays which are known to not only burn the superficial layers of your skin, but also play a key role in the development of skin cancer. For that reason, whether or not you burn, you need a high SPF sunscreen. Keep in mind, however, that no sunscreen can be expected to protect your skin from 100% of the sun’s damaging UVB rays, no matter how high the SPF.
Secondly, since most ultraviolet rays are UVA and therefore not blocked by high SPF sunscreen, you need to be concerned about more than the SPF designation on the label. I recommend you use only broad spectrum products to protect yourself from as much of the UVA spectrum as possible. Keep in mind that while broad spectrum products are good, they still do not provide complete protection. A significant portion of UVA rays, especially energy wavelengths longer than 370 nm, can unfortunately penetrate some of the best formulated sunscreens.
Because even the best formulated sunscreens available today are not perfect, I suggest you limit your time in the sun. Find a shady area to take a break from the harsh ultraviolet rays when outside for extended periods of time, even if wearing a high SPF broad spectrum sunscreen.
But Wait, There’s More (I’m Not Done Yet!)
The bottom line is sunscreen is non-negotiable. If traditional lotions are too much of a bother, then it’s best to try an alternative you can seamlessly incorporate into your life. Whether you prefer lotion, spray or cream, the best sunscreen is the one formulated to meet your needs and used correctly.
The sun’s rays are ultra-powerful and a known carcinogen. You don’t have to burn to damage your skin. And a tan, which is the skin’s defensive mechanism to protect against the sun’s damaging rays, does not completely block harmful ultraviolet radiation. No matter how much you dislike wearing sunscreen, it’s incredibly important to protect you and your family.
So yes, wear high SPF broad-spectrum sunscreen. Apply it liberally. Reapply it often. But those efforts are still not enough. Protect your skin from the sun’s damaging rays by wearing protective clothing such as hats and long sleeved shirts. Slip on some sunglasses. Most importantly, when possible, avoid midday sun. Choose to participate in outdoor activities in the morning and late afternoon. Try to avoid direct sun exposure between 10:00am – 3:00PM. Seek shade when possible. Be sun smart!
Fayne Frey, M.D., is a board-certified clinical and surgical dermatologist practicing in West Nyack, New York, where she specializes in the diagnosis and treatment of skin cancer. She has consulted for numerous media outlets, including NBC, USA Today, and, the Huffington Post, and educates consumers on effective skincare treatments at FryFace.com. She is a fellow of both the American Academy of Dermatology and the American Society for Dermatologic
originally published June 28, 2021
updated August 6, 2021