Hair loss is a common side effect of breast cancer treatment, and it can be emotionally challenging for patients. They may seek ways to help it grow back, and a new study finds a common hair loss drug may be safe to take in small doses.

Research recently published in the Journal of the American Academy of Dermatology investigated whether oral minoxidil, a hair loss drug found in Rogaine, increases certain side effects for breast cancer patients. Minoxidil dilates blood vessels, so there’s concern it could worsen heart-related chemo impacts.

The findings, though, show that small doses of the drug not only appeared to help regrow hair, but taking it didn’t coincide with any serious heart-related side effects.

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

The study involved 51 women treated for different stages of breast cancer. Among them, 25 had surgery or radiation and chemo, while 26 underwent only surgery or radiation. All took minoxidil for at least a month sometime between 2012 and 2023.

The research showed that all the patients who took a low dose of the drug had improvements in hair growth or stabilization of hair loss within three to six months of starting to take it. They also didn’t have any heart-related side effects that caused more treatments or hospitalizations.

Dr. Kristen Lo Sicco, co-senior author and associate professor in the Department of Dermatology at NYU Grossman School of Medicine, says, “Based on these findings, minoxidil has been shown to be safe for patients while also being effective. 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.”

The researchers say that further studies are needed to confirm the results, including in patients with different chemo treatments or with different forms of cancer. They also note that one limitation of the study is that certain heart-related issues could have been present but not been reported because the patient didn’t notice any symptoms.