New nonhormonal medications for menopausal vasomotor symptoms (like hot flashes) are now available. Two drugs, fezolinetant (Veozah®) and elinzanetant (Lynkuet®), belong to a new class of drugs that target the brain’s thermoregulatory center. Clinicians have quickly adopted them, especially for breast cancer survivors and women older than 65. Learn more about how these drugs work, potential side effects, and whether they might make sense for you.
Addressing the most common menopause symptoms
Women experience varied physical, mental, and emotional symptoms before and after menopause. Vasomotor symptoms are considered the hallmarks of menopause and occur in 60-80% of women. They most often include hot flashes, night sweats, and even cold flashes. Vasomotor symptoms occur when estrogen levels fluctuate during this period and interrupt the body’s temperature regulation.
While vasomotor symptoms can be treated with hormone replacement therapy (HRT), some individuals cannot or choose not to use hormones. Clinicians don’t usually recommend HRT for individuals with hormone-responsive cancer or those older than 65 due to potential increased health risks. Previously, few nonhormonal therapies worked well without side effects.
A new class of drugs called neurokinin receptor antagonists came on the market to treat menopause-related vasomotor symptoms. Read more to learn how they work, and what evidence we have that they’re safe and effective.
How neurokinin receptor antagonists work in the brain
To understand how these novel drugs function, it helps to look at the brain’s internal thermostat. Deep inside the hypothalamus sits a group of neurons known as the KNDy (“candy”) neurons. They’re a cluster of brain cells that act like a thermostat, named for the three signaling molecules they express: kisspeptin, neurokinin B, and dynorphin.
Under normal, pre-menopausal conditions, estrogen acts as a natural brake on these neurons. When estrogen levels plunge during menopause, the body removes this brake. The KNDy neurons become hyperactive and release excessive amounts of a brain chemical called neurokinin B. This chemical binds to receptors, triggering a false “overheating” alarm that manifests as a sudden hot flash or night sweat.
Unlike traditional HRT, which replaces missing estrogen to quiet these neurons, neurokinin receptor antagonists act like a molecular shield. By directly binding to neurokinin receptors, they block hyperactive signaling without introducing hormones into the body.
The initial clinical research data on nonhormonal menopause medications
The U.S. FDA approved two new medications to treat moderate-to-severe vasomotor symptoms: fezolinetant (in 2023) and elinzanetant (in 2025). Fezolinetant blocks the neurokinin-3 (NK3) receptor, and elinzanetant blocks both NK3 and neurokinin-1 (NK1) receptors.
The primary approval profiles for these medications rest on key randomized controlled trials. The raw data from these pivotal clinical programs details their performance.
- Study Sizes: Combined, the phase III trials evaluated 2,800 postmenopausal individuals experiencing moderate-to-severe hot flashes.
- General Outcomes: Data showed a statistically significant reduction in hot flash frequency and severity compared with a placebo at weeks 4 and 12. Women taking the medication experienced an average drop of about 2.5 hot flashes per day. Improvements were maintained over 52 weeks. Recent patient-reported outcome data from international trials further confirm rapid improvements in menopausal quality of life and sleep.
- Side Effects: Study participants reported abdominal pain, diarrhea, insomnia, back pain, and hot flashes. Crucially, the SKYLIGHT 4 trial revealed that approximately 1-2% of participants experienced elevations in liver enzymes. Fezolinetant is contraindicated in patients with liver cirrhosis, severe kidney problems, and those taking CYP1A2 inhibitors.
- Study Sizes: The OASIS clinical program studied almost 1,500 participants globally.
- General Outcomes: Elinzanetant rapidly reduced the frequency and severity of vasomotor symptoms by week 4, and this reduction was sustained through 26 weeks. Because it also blocks the NK1 receptor (which is closely linked to sleep and mood pathways), the medication also improved sleep quality and overall menopausal quality of life.
- Side Effects: The clinical trials indicated that the drug was well tolerated. The most common side effects included mild headaches and sleepiness. It did not demonstrate the same signal for liver enzyme elevation seen with selective NK3-only blockers.
Real-world update: how the medications are performing
As these therapies have transitioned from highly controlled clinical trial settings to products available at local pharmacies, broader registry data have yielded vital insights into clinical practice patterns and real-world behavior.
Groups with a high interest in neurokinin receptor antagonists
Breast Cancer Survivors: Hormone-receptor positive breast cancers are fueled by estrogen and progesterone. Treatment often involves anti-estrogen therapy, causing intense, treatment-induced hot flashes. As published in May 2026, an analysis of fezolinetant users reported that 20.5% had a diagnosis of breast cancer, confirming their interest in treating vasomotor symptoms with a nonhormonal option.
Research has supported the use of neurokinin receptor antagonists for breast cancer survivors. A phase III clinical trial of elinzanetant reported significant reductions in hot flashes and night sweats for people being treated with anti-estrogen therapy for hormone receptor-positive breast cancer. Researchers are conducting similar studies of fezolinetant.
Women Over Age 65: Older women are also using the new nonhormonal menopause medications. Accounting for over 13.3% of fezolinetant users, these individuals are typically past the age when prescribers recommend traditional hormone therapy.
The adherence challenge and liver safety tracking for fezolinetant
Clinical trial results are promising, but don’t always reflect what happens in everyday life. Real-world data show that while the drugs are highly effective when taken consistently, many individuals do not take them long-term.
Real-world monitoring highlighted persistent use and compliance with clinical protocols as problematic with fezolinetant. In a large-scale retrospective cohort study, only about 20.5% of patients demonstrated persistent use — defined as refilling their second prescription. The drugs only work while being taken, and stopping early means symptoms are likely to return.
Additionally, the FDA mandates baseline liver function testing and testing at 1, 2, 3, 6, and 9 months. Real-world analysis shows that only about 42% of persistent users received the required liver function testing during the first 3 months of treatment. This underscores a strong need for better provider and patient education.
For elinzanetant, real-world data align with its clinical trial data. Providers report high patient satisfaction, particularly due to its dual benefit of suppressing nighttime hot flashes while simultaneously reducing menopause-related insomnia and sleep disturbances.
Hormonal vs. nonhormonal treatment: navigating the options
There’s no single right answer on whether to choose hormonal or nonhormonal treatment options for vasomotor symptoms of menopause. However, there are good options — and the right choice depends on your health history, lifestyle preferences, and risk profiles.
The hormonal pathway (menopausal hormone therapy)
For decades, systemic estrogen (with progesterone for those who still have a uterus) has stood as the gold standard for vasomotor symptom relief, reducing hot flash frequency by up to 80-90%. However, some forms of estrogen and progesterone carry risks for certain groups, and modern formulations are important (learn more about menopause hormone therapy).
- Pros: Highly effective; protects bone density; improves vaginal dryness; reduces risk of Alzheimer’s disease, heart disease, and colon cancer.
- Cons: Many clinicians do not prescribe hormone therapy for individuals with a history of breast cancer, stroke, blood clots, liver disease, or unexplained uterine bleeding. Some research indicates that risk profiles rise if HRT is initiated more than 10 years after menopause onset or after age 60.
The nonhormonal pathway (neurokinin antagonists)
The arrival of neurokinin blockers has dramatically shifted the landscape for women who cannot or choose not to take hormones. Previously, the only FDA-approved nonhormonal treatment for hot flashes was paroxetine (Brisdelle), an SSRI (selective serotonin reuptake inhibitor) antidepressant with side effects.
- Pros: Do not stimulate breast tissue or the uterine lining; no risk of blood clots. They act rapidly (often within days) and offer an evidence-based alternative for breast cancer survivors or older postmenopausal women.
- Cons: Neurokinin blockers require daily oral compliance and can be expensive depending on insurance coverage. Fezolinetant demands a rigorous schedule of follow-up blood tests to check liver health, and many people do not continue treatment.
Ultimately, the choice is no longer binary. With modern hormone therapy and new nonhormonal options, women have new, scientifically validated avenues to regain comfort and control over their daily lives.
Frequently asked questions
Q: Are neurokinin receptor antagonists considered hormones?
A: No. Fezolinetant (Veozah) and elinzanetant (Lynkuet) are completely nonhormonal chemical entities. They operate entirely within the brain’s neurological pathways to block temperature signals related to menopause rather than altering circulating estrogen or progesterone levels.
Q: Can I take fezolinetant or elinzanetant for hot flashes if I had breast cancer?
A: Yes. Because they’re nonhormonal and do not stimulate estrogen receptors, clinicians actively prescribe them to breast cancer survivors. However, a 2026 review called for long-term safety studies to clarify the cancer risk profile of fezolinetant. You should always consult your oncologist before starting any new medication.
Q: Why do I need blood tests to take fezolinetant?
A: Fezolinetant can cause elevated liver enzymes in a small percentage of users, which could indicate liver strain. The FDA requires blood tests before starting and during the first 9 months of therapy to monitor your liver health.
Q: How does elinzanetant differ from fezolinetant?
A: Fezolinetant targets a single receptor (NK3). Elinzanetant is a dual antagonist that targets two receptors (NK1 and NK3). This dual action helps control hot flashes while providing an added benefit of improving sleep quality and reducing nighttime sleep disturbances.
Q: Are elinzanetant and fezolinetant covered by insurance?
A: Most major insurance companies cover nonhormonal treatments for menopausal vasomotor system complaints. Pricing is high for noninsured individuals, but discount programs can help reduce costs.
