Spending a few minutes in the sun today without sunscreen, adding a little more tomorrow, and arriving at summer with skin that’s “accustomed” to the sun. That’s the promise of the so-called solar callus, a notion circulating on TikTok that gives a new name to a long-standing tip: building a base tan before vacation. The American Academy of Dermatology warns that this practice is not scientifically supported and that UV radiation damage accumulates with every exposure.
What is the “solar callus” and where does the myth come from
The name borrows the logic of the calluses that form on hands or feet due to repeated rubbing. According to the viral theory, exposing the skin to the sun without protection would cause the skin to thicken and form a barrier capable of preventing future burns.
The American Academy of Dermatology clarifies that the “solar callus” is not a phenomenon recognized by medicine. Both the tanning and the thickening that can appear after UV exposure are responses of the skin to damage.
What happens if you tan without actually burning?
When you tan from sun exposure, your skin produces more melanin, the pigment that gives color. It is a defensive response that offers only limited protection against UV rays. Therefore, you can accumulate solar damage even if the skin never turns red. Over time, repeated exposure favors the appearance of dark spots and premature wrinkles and increases the risk of skin cancer.
How to protect your skin from the first day at the pool
For an outdoor afternoon, combine sunscreen, shade and garments that cover the skin. These are the recommendations of the National Ministry of Health and the American Academy of Dermatology.
- Choose a broad-spectrum sunscreen, SPF 30 or higher. Look for one that is water-resistant if you plan to swim or engage in physical activity.
- Reapply every two hours and after leaving the water or sweating. Remember to cover also the ears, the nape of the neck and the instep.
- Prioritize shade between 10 and 4. Add a wide-brimmed hat, sunglasses with UV protection and lightweight clothing that covers the skin.
