A WOMAN’S YEARS-LONG TRANSITION to menopause, or perimenopause, often comes with vasomotor symptoms: hot flashes and night sweats. But women who take endocrine therapy, which blocks estrogen or lessens its effects to treat or prevent breast cancer, can experience abrupt symptoms.

“It’s very disturbing, psychologically and physically,” says Fatima Cardoso, a medical oncologist at Champalimaud Clinical Centre in Lisbon, Portugal, and president of the ABC (advanced breast cancer) Global Alliance. “It’s a situation that has a significant impact on a woman’s life.”

Some women find the side effects so severe they discontinue endocrine therapy, which may increase their recurrence risk. Additionally, women with a history of hormone receptor-positive breast cancer should not take hormone replacement therapy, which can relieve menopause-related hot flashes.

The Food and Drug Administration (FDA) had previously approved two nonhormonal remedies to manage symptoms of menopause. Veozah (fezolinetant) is a targeted therapy, but it isn’t well studied in women with breast cancer. The antidepressant paroxetine is also approved to manage hot flashes but isn’t recommended for people taking the endocrine therapy tamoxifen.

On Oct. 24, 2025, the FDA approved Lynkuet (elinzanetant) to treat moderate to severe vasomotor symptoms caused by menopause in women ages 40 to 65.

However, a study published June 2, 2025, in the New England Journal of Medicine shows that women who took this nonhormonal drug had fewer episodes of hot flashes and night sweats while taking endocrine therapy for hormone receptor-positive breast cancer. The phase III clinical trial involved 474 women ages 18 to 70. A group of 316 patients took a once-daily, 120-milligram dose of Lynkuet for a year, while 158 patients took a placebo for 12 weeks, then Lynkuet for 40 weeks.

Women who took Lynkuet reported having an average of 11.4 vasomotor episodes a day going into the trial, compared with 11.5 in the placebo group. After four weeks, participants in the Lynkuet and placebo groups had 6.5 and three fewer daily episodes, respectively, than they did at the start. By week 12, daily episodes had decreased by 7.8 and 4.2 from the start of the trial. In addition, people taking Lynkuet reported fewer sleep disturbances and a greater improvement in quality of life than those who initially received a placebo.

Patients in the placebo group experienced similar symptom relief within days of switching to Lynkuet, says Cardoso, who was an author of the study.

During the first 12 weeks, 69.8% of people taking Lynkuet reported at least one side effect, such as sleepiness, fatigue and headache, compared with 62% of people in the placebo group. However, 91.6% of women who completed the full year of treatment chose to continue taking the drug for an additional two years, which suggests it’s well-tolerated, says Halle Moore, the director of breast medical oncology at Cleveland Clinic Cancer Center.

“This was an important study to specifically look at this patient population for whom there’s a real need for nonhormonal treatment options,” says Moore, who was not involved in the research.

One limitation of the study is its lack of racial and ethnic diversity—88.2% of participants were white—and additional research is needed to assess adherence to endocrine therapy beyond the first year, the authors wrote. In future trials, Cardoso says she wants to include men, who can also experience hot flashes from cancer treatment.

Lynkuet’s U.S. approval could potentially provide life changing relief for women experiencing hot flashes and night sweats from endocrine therapy, Cardoso says. “We can improve their quality of life, but we can also improve the cancer control by allowing them to continue the [endocrine] treatment,” she says.