Tanning beds
This is the one skip on the whole list that isn't really about skincare. It's about skin cancer. Major health groups, including the World Health Organization, put tanning beds in the same cancer-causing category as cigarettes, and using them clearly raises your risk of skin cancer. That's why most US states legally bar minors from tanning salons. There's no safe amount. A self-tanner from the drugstore gives you the color with none of the UV. Hard skip.
what the evidence says
AAD and WHO classify indoor tanning devices as carcinogenic; indoor tanning raises squamous- and basal-cell carcinoma risk, and the AAP supports laws restricting minors' access.
stage a kind intervention
Got a friend who swears by this? Send them the receipts. The message is pre-written to be kind, because the product is the problem, not your friend.
“Saw this and thought of you. No judgment, just receipts on tanning beds: https://skinformed-gamma.vercel.app/ingredient/indoor-tanning/”
sources
note:Skinformed is general education, not medical advice. It doesn't know your skin, can't diagnose anything, and is no substitute for a clinician. If something on your skin hurts, spreads, or worries you, that's a doctor visit, not a product search.