With the rise of social media, information both true and false is able to spread like wildfire, reaching hundreds of thousands or even millions of people in an instant. For true information, that can be a positive development, but, for the spread of misinformation it can be dangerous. One such troubling myth that is rampant on social media is that you can build a “solar callus” to protect your skin from sunburn. This solar callus, or sun tolerance, is not backed by any science and is dangerous. It can increase the risk of all skin cancers including melanoma – the most dangerous form of skin cancer.
What is a solar callus?
Sun tolerance or a solar callus is a made-up term that describes the belief that you can “build up” a tolerance to sun exposure so that you can safely tan or get sunburns without harm. This is not supported by medical science. Dermatologists and the Skin Cancer Foundation emphasize that there is no such thing as a safe or healthy tan. Any change in skin color is a sign of skin damage.
UV radiation from the sun is a proven human carcinogen, and even brief unprotected exposure damages skin cell DNA, triggering melanin production that leads to tanning or burning. Sun damage is cumulative, and early-life exposure increases lifetime skin cancer risk.
Getting led astray
A recent FDA proposal that would have prevented anyone under 18 from using an indoor tanning bed was withdrawn by Secretary of Health and Human Services, Robert F. Kennedy, Jr. Secretary Kennedy himself is a proponent of sun exposure including the solar callus and has made statements that encourage people not to use sunscreen. He also promotes sun exposure as a way to produce Vitamin D, despite dermatologists’ warnings that the risk of skin damage far outweighs any Vitamin D benefits.
The Science
- No tolerance: The body does not “get used to” UV radiation; repeated exposure increases cumulative DNA damage.
- Tanning beds are dangerous: They emit UVA and UVB at intensities far above natural sunlight — up to 15 times more UVA than on Earth’s surface — and are classified as Group 1 carcinogen by the World Health Organization.
- Vitamin D alternatives: Vitamin D can be obtained without UV exposure from foods such as: salmon, canned tuna, sardines, herring and other oily fish, mushrooms, and eggs or by taking a Vitamin D supplement.
- Skin cancer risk: Even a few minutes of unprotected sun daily can raise skin cancer risk over time.
Bottom line
While Secretary Kennedy and some influencers promote sun exposure as a way to “build tolerance” or get Vitamin D, medical experts strongly advise against it. The only safe approach is to limit exposure to the sun’s harmful UV rays and obtain Vitamin D through safe dietary or supplemental sources.
At IMPACT Melanoma we encourage you to be sun safe and adopt healthy habits including the following:
- Check the UV index daily. If it is higher than 3, put on sunscreen SPF 30 or higher and reapply every two hours.
- Wear protective clothing, hats, and sunglasses.
- Seek shade.
- Get Vitamin D from your diet or a supplement.
- Get an annual skin check with a dermatologist. It only takes a few minutes and it can save your life.
The science is clear and consistent, UVA and UVB exposure are dangerous and cause skin cancers including melanoma, the deadliest form of skin cancer. Attempting to build sun tolerance or a sun callus has no basis in science and dermatologists as well as the skin cancer foundation strongly urge against this dangerous practice.
Learn more about Melanoma Facts.
