For decades, if a woman could not or would not take estrogen, her options for hot flashes were not great. SSRIs and SNRIs helped some women modestly, and came with sexual side effects, weight changes, and the baggage of being antidepressants. Gabapentin caused sedation. Clonidine required blood pressure monitoring. Botanicals and herbal supplements had inconsistent evidence and variable quality. Women were largely told to wait it out. That changed in 2023 when the FDA approved fezolinetant, sold under the brand name Veozah, for moderate to severe vasomotor symptoms. It is the first drug in a new class: a neurokinin-3 receptor antagonist. And unlike everything that came before it, it targets the actual neurological mechanism behind hot flashes rather than offering a workaround. It is worth taking seriously. It is also worth understanding clearly, so you can make an informed decision about whether it belongs in your care plan.
Why Hot Flashes Happen and How Fezolinetant Is Different
Hot flashes are not just about low estrogen in isolation. They involve a part of the brain called the hypothalamus, and specifically a cluster of neurons called KNDy neurons that become overactive when estrogen drops. These neurons use a signaling molecule called neurokinin B, which binds to the NK3 receptor. When that receptor is overstimulated, it dysregulates the body's thermostat. The result is a hot flash. Fezolinetant blocks that NK3 receptor directly. It does not contain estrogen. It does not act like estrogen elsewhere in the body. It is acting at the source of the problem in the brain. This is genuinely novel and it matters. Especially for women who cannot use estrogen due to a history of hormone-sensitive breast cancer, blood clots, or other contraindications.
What the Clinical Data Shows
The trials that led to FDA approval showed that fezolinetant at 45 mg daily reduced the frequency of moderate to severe hot flashes by roughly 60 to 65 percent from baseline at 12 weeks, compared to roughly 45 percent with placebo. A meaningful percentage of women in the trials saw reductions of 90 percent or more. Improvements in sleep quality were also documented, which makes sense given that nocturnal hot flashes are a primary driver of midlife insomnia. The drug reaches meaningful effect within the first two to four weeks for most women, which is faster than SSRIs typically take to show vasomotor benefit.
What You Need to Know About Safety
No drug is without considerations, and fezolinetant has some that require attention. Liver enzyme elevations were seen in a small percentage of women in trials. The FDA requires liver function testing before starting the drug and periodically thereafter. This is not a reason to avoid it in appropriate candidates, but it is a reason to be working with a clinician who is actually monitoring it rather than just handing you a prescription and sending you on your way. GI side effects, primarily diarrhea and abdominal discomfort, were the most common side effects and tended to be mild and transient for most women. Fezolinetant is metabolized by an enzyme called CYP1A2. If you are taking medications that are strong CYP1A2 inhibitors, including some antibiotics, antifungals, and psychiatric medications, you cannot safely take fezolinetant with them. This is a critical drug interaction that requires a complete medication review before prescribing.
Where It Fits and Where It Does Not
Fezolinetant is not hormone therapy and it does not offer the systemic benefits that estrogen does, which include bone protection, cardiovascular support in appropriately timed initiation, cognitive support, and urogenital health. If you can take estrogen and it is appropriate for you, hormone therapy remains the most comprehensively beneficial approach. Where fezolinetant genuinely fills a gap is for women who cannot use estrogen and who are suffering significantly from vasomotor symptoms. It is also a reasonable option to consider while transitioning off estrogen, or in women who want to reduce vasomotor symptoms without any hormonal exposure. I also sometimes consider it as a bridge or complement in women whose hot flashes are not yet fully controlled on hormone therapy while we are titrating toward an optimal dose. What I do not think it should be is the reflexive alternative offered to women who could benefit from hormone therapy but whose doctors are reluctant to prescribe it. Fezolinetant is a legitimate treatment for a legitimate indication. It should not be a workaround for a physician's discomfort with HRT.
Frequently Asked Questions
Who is fezolinetant appropriate for? Women with moderate to severe hot flashes who cannot use estrogen, including women with a history of hormone-sensitive breast cancer, blood clots, or other contraindications to hormone therapy.
How quickly does it work? Most women see meaningful reduction in hot flash frequency within two to four weeks. The full effect is typically seen by twelve weeks.
Does it replace hormone therapy? No. It does not provide the bone, cardiovascular, cognitive, or urogenital benefits of estrogen. It addresses vasomotor symptoms specifically.
What monitoring is required? Liver function tests before starting and periodically during treatment. A full medication review for CYP1A2 interactions before prescribing.
Can it be used alongside hormone therapy? In some cases, yes. This is a conversation to have with your prescribing clinician based on your individual situation. If you are ready to get individualized care that reflects where the science actually is, book a complimentary discovery call at doctoranat.com. No pressure, no commitment. Just a real conversation about where you are and what is possible.
Book your complimentary discovery call at doctoranat.com
Dr. Anat Sapan is a board-certified OB-GYN and menopause specialist, exclusively focused on personalized bioidentical hormone therapy for women in their 40s, 50s, 60s, and beyond. She serves patients via telemedicine in California, Florida, New York, and Illinois.
Anat Sapan, MD
Contact Me
