This summer, a trend has emerged on social media platforms like TikTok and Instagram where users, particularly from Gen Z, are closely monitoring the daily UV index. However, instead of using this information to avoid sun exposure, many are seeking out times when the UV index is highest in order to tan more quickly. At the same time, some influencers have questioned the safety and necessity of sunscreen use.
Dermatologists warn that these behaviors carry significant health risks. Ultraviolet (UV) radiation from the sun can cause damage to all skin types, leading not only to immediate effects such as sunburn but also to long-term consequences including premature aging, hyperpigmentation, and increased risk of skin cancer.
Y. Linda Liou, DO, assistant clinical professor in the Department of Dermatology at UC San Diego School of Medicine, addressed these concerns by explaining how the UV index works and why intentional sun exposure during peak hours can be harmful.
“I actually love that people are paying attention to the UV index — it means they’re thinking about sun exposure. But what worries me is how it’s being used: instead of avoiding high UV times, people are chasing them to tan faster. A tan may look like a glow, but it’s really your skin’s SOS signal that DNA damage has already happened. You don’t see it right away, but the harm is happening underneath,” Liou said.
She explained that “the UV index is basically a weather report for how strong the sun’s radiation is. It takes into account things like time of day, altitude, cloud cover and ozone levels. The scale runs from 1 to 11+, and the higher the number, the faster your skin can burn or get damaged. At a UV index of 11, for example, some lighter skin tones can burn in under 5 minutes. But even if you are darker skinned and you don’t burn easily, your skin cells are still getting hit with invisible radiation damage.”
Liou warned about both short- and long-term dangers associated with tanning during peak UV hours: “When you lay out during peak UV, you’re getting a blast of radiation at its strongest. On the surface you might see a tan or burn, but underneath, UV rays are breaking DNA, stressing out skin cells and weakening your skin’s immune defenses.”
“Short-term effects include sunburns, tans and more breakouts of things like cold sores. Over time, UV damage can lead to wrinkles, skin thinning, uneven pigmentation and increased risk of skin cancers that can be life threatening, like melanoma,” she continued.
She emphasized that “no skin tone is immune,” noting that while darker complexions may not burn as easily as lighter ones do, they remain vulnerable to cumulative UV damage which may result in conditions such as hyperpigmentation or delayed diagnosis of skin cancers.
Addressing myths about tanning safety—such as claims that a “base tan” offers protection—Liou clarified: “One of the biggest myths is that a ‘base tan’ protects you. The truth is, a tan is your skin’s response to damage — it translates to your cells pumping out melanin…to shield the rest of your skin cell from more injury. That tiny bit of protection is nowhere near as strong as sunscreen…”
Responding to misinformation online regarding sunscreen safety or necessity—which includes allegations about toxicity or environmental impact—Liou stated: “It’s easy to feel overwhelmed by all the mixed messages online. But here’s the fact: sunscreen is safe, effective, and one of the simplest ways to prevent skin cancer and premature aging.”
She added clarification on common concerns:
“Sunscreen is toxic and harmful: Some studies in mice found signs of malignant transformation when animals were exposed to very high doses…under conditions that don’t reflect typical human use…If you want to minimize any…risks mineral sunscreens (zinc oxide titanium dioxide) are great alternatives.
Sunscreen is bad for the environment: Not all sunscreens have a negative impact on coral reefs…look for mineral sunscreens or ‘reef-safe’ options.
Sunscreen will cause vitamin D deficiency: The truth is…the sun is a really unreliable way to get vitamin D because it varies by season skin tone and geography —and the UV damage outweighs benefits…”
Liou highlighted an often-heard regret among older patients who developed skin cancers: “I wish I had worn more sunscreen when I was younger.” She pointed out there are now many different forms available—including lotions sprays gels sticks—and recommended choosing one suited for each individual.
For those wanting safer ways to enjoy sunny days beyond standard advice (“wear sunscreen and a hat”), Liou suggested practical measures such as seeking shade during midday hours (before 9 a.m., after 4 p.m.), checking daily UV forecasts on smartphones—even on cloudy days—and using broad-spectrum SPF 30+ products with correct application amounts.
She also mentioned photo-protective clothing options (UPF-rated shirts wide-brim hats sunglasses), laundry additives like SunGuard for extra garment protection against UV rays without new purchases; plus dietary supplements derived from ferns (polypodium leucotomos) as additional—but not substitute—protection strategies.
