“In general, I am wary of anyone soaking up more of the sun’s rays to lighten their hair,” says Noreen Galaria, MD, a board-certified dermatologist and founder of Inner Glow vitamins. “Most people never bother to spot test [hair lighteners] before application, and we do see patients coming in with reactions in the summer months.” DIY hair lightener-induced chemical burns are a real thing and, to add insult to injury, your strands may not even turn out “sun-kissed” as promised. Abby Haliti, expert colorist and the founder of New York City’s Abby Haliti Color Studio, says that in her experience, hair often looks “blotchy and uneven” after using a sun-activated lightener.