Women worried about losing their locks during chemotherapy can safely take hair-loss drugs during breast cancer care, a new study says.

Minoxidil — the active ingredient in the over-the-counter Rogaine — is commonly prescribed for hair loss, but is also used to dilate blood vessels as a treatment for high blood pressure.

Because of this effect on blood vessels, experts had been worried that minoxidil might increase heart-related side effects of chemotherapy and lead to chest pain or shortness of breath.

But the new research has concluded that a low-dose minoxidil pill taken during or after breast cancer treatment can regrow hair in female patients without any serious side effects.

“Our results should offer reassurance to breast cancer patients that there is indeed a safe way to combat their hair loss,” said co-lead researcher Devyn Zaminski, a medical student at NYU Grossman School of Medicine.

The threat of hair loss can cause some cancer patients to not undergo needed chemotherapy, to avoid a blow to self-confidence in the middle of their health crisis, researchers said in background notes.

For the study, researchers combed NYU Langone Health’s electronic record system from 2012 to 2023.

The team identified 51 breast cancer patients who’d taken minoxidil for longer than one month, and whose charts noted how well they did on the drug.

Of the women, 25 had chemotherapy on top of some combination of surgery or radiation, while 26 were treated with surgery or radiation.

All of the women who took low-dose minoxidil experienced either hair regrowth or a stabilization of their hair loss within three to six months of starting the therapy, researchers found.

“Based on these findings, minoxidil has been shown to be safe for patients while also being effective,” said co-senior researcher Dr. Kristen Lo Sicco, an associate professor of dermatology at NYU Grossman School of Medicine. 

“The effectiveness of minoxidil may therefore help patients restore their sense of self and some control in a situation where it has been visibly taken away,” Lo Sicco added in a news release from the university.

However, additional research is needed to confirm these findings, and to test whether minoxidil would be safe in people with other types of cancer or undergoing different chemo regimens, Lo Sicco said.

The study was funded by NYU Langone Health, and appears in the Journal of the American Academy of Dermatology.