Does Sunscreen Prevent Tanning?
We all know that we’re supposed to wear sunscreen. We all know just how damaging the sun’s rays can be. We all know that we don’t want to get skin cancer. Right?
But we also want a perfectly even tan — the golden skin that makes us look and feel radiant.
Does sunscreen prevent tanning? That is, if we do what our heads tell us to do (wear sunscreen), are we sacrificing what our hearts desperately want (an amazing tan)?
Let’s take a look at the science so that we can answer once and for all this pressing summertime question: Does sunscreen prevent tanning?
Two Kinds of Sun Rays
The question is more complicated than you might think. But here’s a good place to start: Did you know there are two kinds of sun rays? Ultraviolet light includes both aging rays (UVA rays) and burning rays (UVB rays). As you might have guessed, UVA rays are what age your skin in the long-term and UVB rays are what cause you to burn in the short-term.
But here’s something you may not know: UVA rays cause tanning, while UVB rays cause burning. Here’s why …
UVA rays sink deep into your skin where they cause long-term damage. As they do, they affect your skin’s pigment, turning it a darker shade. UVA rays are always present when the sun is up, and they can even pass through glass and clouds. Ever heard that you can burn on a cloud day? Well, you can certainly tan.
UVB rays, conversely, only touch on your skin’s surface where they cause intense burning if you stay out in the sun too long. UVB rays are most powerful at midday, and they cannot penetrate glass or clouds.
Is Your Sunscreen ‘Broad Spectrum’?
Not all sunscreen blocks both UVA and UVB rays. In fact, only two chemicals approved by the US Food and Drug Administration block UVA rays — tanning rays. Those chemicals are avobenzone and zinc oxide.
You can find sunscreen products that don’t include either, which can certainly help you tan. But, if you want to stay safe, look for products marked as “broad spectrum.” Only sunscreen products that block both UVA and UVB rays can label themselves as broad spectrum.
What About SPF?
No sunscreen blocks all ultraviolet rays. In fact, SPF is the measure of how much light a product blocks. For example, SPF 15 products block 93% of UVB rays, while SPF 30 blocks about 97% of UVB rays. But, SPF only measures UVB blockage — not UVA blockage. So it really only measures effectiveness in burning prevention, not tanning prevention. There is no widely accepted measure of UVA blockage.
So, Does Sunscreen Prevent Tanning?
Back to the original question: Does sunscreen prevent tanning? No, it does not. Sunscreen is essential to protecting your skin against harmful UVB rays that cause you to burn (and that can lead to skin cancer). But it’s equally as important to wear a broad spectrum product that also blocks UVA rays, which age your skin and can have serious health consequences.
How, then, do you tan while wearing sunscreen? You can wear plenty of sunscreen while outdoors for the day and still tan safely. The best tan is a natural tan, one that occurs naturally as you’re wearing sunscreen. That sunscreen is going to let in a healthy amount of rays, just enough to affect your skin’s pigment but not enough that it causes significant damage.
The only mistake you can make is confusing UVA and UVB, and assuming that a lower SPF is going to help you tan. It’s not. A lower SPF is only going to increase the likelihood that you burn, and it will have no impact on UVA rays and your ability to tan.
Final Thoughts on Sunscreen and Tanning
I wrote recently about sunscreen expiration dates, and I covered a lot of the science behind sunscreen in that post. But I can’t tell you enough: Don’t take drastic measures to try to get a tan. Go about it naturally. Get outdoors during the nicest times of the year, which is what makes spring and summer so wonderful. But wear plenty of sunscreen and let your tan occur naturally. You may not realize it now, but you’ll be helping to keep your skin happy and healthy for decades to come.
Have you had a good or bad experience with sunscreen and tanning? If so, let us know in the comments section below. Or, you can always send a message through our contact page.