It’s a shocking warning every woman should hear — your hair straightener could be doing more than styling.

A major Emory University study found that chemical relaxers and hair straightening treatments may raise cancer risk by as much as 166%, especially for those using them several times a year. “The numbers are alarming,” one researcher said. “Women deserve to know the risks hiding in these products.”

The study tracked more than 46,000 women for 13 years and found strong links between straightener use and pancreatic, thyroid, and lymphatic cancers. The culprit? Formaldehyde, a known carcinogen that turns into harmful gas when heated — the same gas many inhale during home treatments or salon visits.

Experts say better regulation is urgently needed, especially as many women — particularly Black and Latina women — rely on these products regularly. Several U.S. states are already moving to ban formaldehyde in cosmetics.

As one health advocate put it, “Beauty should never come at the cost of your life.” Maybe it’s time to let natural shine mean more than just hair.