General Discussion

What Dermatologists Think Of MAHA’s Tanning Logic

The dermatologists we spoke to had plenty to say about MAHA’s “solar callus” ― or “sun tolerance” ― theory, which holds that gradually building up a “base tan” helps the skin tolerate sun exposure without burning.

“There is a small kernel of physiologic truth here that is being stretched into something it is not,” Del Campo said. “Yes, repeated UV exposure causes the skin to produce more melanin, and yes, that pigmentation does offer a tiny amount of protection against future burning. But a tan is your skin telling you it has been injured. It is a damage response, not a shield.”

“Solar callus” is a made-up, non-medical term.

“It’s not a recognized dermatologic concept. You will not find it in any textbooks or peer-reviewed literature,” Del Campo said. “It is essentially a marketing phrase that has taken on a life of its own through social media.”

Rossi stressed, too, that a tan is not protection; it’s evidence of real damage.

“Especially if you get red or pink or burn before,” Rossi said. “Your skin tanned because DNA injury already occurred. The melanin response is reactive, not preventive. An SPF equivalent of a deep tan is roughly SPF 3-4, which will not protect from another burn.”