Does Sunscreen Prevent Tanning? + How To Tan Responsibly

Everyone's skin care routine is different. Some people opt for goal-specific ingredients, while others like to keep it simple. Regardless of your product lineup, there's one step that should be universal: applying sunscreen. 

If you've ever wondered, "How does sunscreen even work?" you're not alone. We asked clean cosmetic chemist Krupa Koestline and board-certified dermatologist Rebecca Marcus, M.D., to explain. 

"UV rays signal the skin to increase transcription of the tyrosinase gene," Koestline said. Tyrosinase is responsible for the first step in melanin production. 

"Sunscreen works by reducing and limiting the signal to reduce tyrosinase production," she explained. Translation: Sunscreen increases the amount of UV radiation needed to create sun damage on the skin. 

However, there is a difference between the mechanisms behind mineral and chemical formulas. "Chemical sunscreens work by absorbing UV radiation and catalyzing a chemical reaction that transforms these rays into heat, which is then released from the skin," Marcus explained. 

On the flip side, mineral sunscreens create a sun-blocking barrier. "Physical sunscreens physically block UV radiation from reaching the skin by deflecting UV rays," she continued. 

At the moment, zinc oxide and titanium dioxide (common ingredients in mineral SPF) are the only two ingredients the Environmental Working Group has deemed safe for use and effective at protecting the skin from UV damage.

Unfortunately, this answer isn't so simple. Technically, you can still tan with sunscreen on. How tan, however, depends on many things: how easily you tan, what level of SPF you're wearing, what the UV index is at the time of sun exposure, etc.

"SPF refers to 'sun protection factor' and is a measure of the amount of solar radiation required to produce a burn on protected skin versus the amount required to produce a burn on nonprotected skin," Marcus explained. "So, it is still possible to tan or burn with sunscreen on, but it takes a larger dose of UV radiation to do so."

Let's be frank, "There is no such thing as a safe tan," board-certified dermatologist and YouTube creator Andrea Suarez, M.D., FAAD, told mbg. "Tanning is an injury response to UV rays from the sun. The same rays that tan the skin also lead to permanent skin injury, premature skin aging, and increased skin cancer risk."

While lounging under the rays may feel nice and result in a bronzy glow for some, what's happening behind the scenes is not so pretty. That being said, you don't have to kiss goodbye your sun-kissed glow. Enter, sunless tanning products. 

If you've ever been hesitant to lather on SPF for fear that you won't absorb vitamin D, we hear you. It's a common concern, but here are the facts: Despite being called the "sunshine" vitamin, it's actually quite hard to get a sufficient amount of vitamin D from the sun. That's because various factors, like skin tone, time of year, your age, and more, can influence how well your body is absorbing that vitamin D. (We've done a deeper dive on those reasons here, if you're curious). All that to say, you should not avoid sunscreen for this reason.

In fact, researchers recommend taking a multipronged approach to vitamin D 1intake, including high-quality supplementation, consumption of fortified foods, and smart sun exposure (which includes SPF). Suarez explains further, "Because sunscreen does not block 100% of UV rays, some UVB does get through, and this is enough to allow for some vitamin D production." The same circumstances that come with sunscreen tanning are true here: so you should be applying (and reapplying) often to protect your skin.

That was a lot, so let's review. You can still get a suntan while wearing sunscreen, though proper application will prevent most of the UV rays from penetrating the skin, thus preventing a tan. You can still absorb vitamin D even if you're wearing sunscreen, but those with a deficiency should consider supplementing to meet adequate levels.