What is fezolinetant and does it help with hot flashes?
Fezolinetant is a daily non-hormonal tablet for moderate to severe hot flashes caused by menopause, and in a 12-week trial women taking 45 mg had 2.53 fewer hot flashes a day than women on a placebo tablet. It is FDA-approved in the US; in the UK it is MHRA-licensed, has been on private prescription since 5 January 2024 and has been recommended by NICE (TA1143, 2026) when HRT isn't suitable or wanted, which places it among the menopause treatments worth knowing about.
In plain words, fezolinetant blocks the brain's hot-flash signal (hot flushes in the UK) without being a hormone treatment. That makes it of interest to women who cannot take, or would rather not take, HRT, usually called hormone therapy in the US. It also carries an FDA boxed warning for rare but serious liver injury, which is why regular liver blood tests come with the prescription.
What is fezolinetant and how does it work?
Fezolinetant belongs to a class of medicines called neurokinin 3 (NK3) receptor antagonists. Because it acts on a brain signal and not on hormone levels, it sits in the nonhormonal group of treatments (non-hormonal in UK usage). It is available on prescription only.
It is one of several non-hormonal options. Some SSRIs and SNRIs and gabapentin also reduce flashes, and CBT helps with flashes, sleep and mood. Fezolinetant's one licensed use is hot flashes, which is why the trial evidence below is about how often flashes happen and how severe they are.
Does fezolinetant reduce hot flashes?
In the main 12-week trial, fezolinetant reduced hot flashes more than a placebo tablet did. The trial was published in the Journal of Clinical Endocrinology & Metabolism in 2023 (Neal-Perry et al.) and analysed 500 women aged 40 to 65, with a mean age of about 54. By week 12, women taking 30 mg had 1.86 fewer hot flashes a day than women on placebo, and women taking 45 mg had 2.53 fewer.
Read as a percent change from where each group started, hot flash frequency fell by 58.6% on 30 mg and by 64.3% on 45 mg. On placebo it fell by 45.4%. A tablet with no active ingredient also brought a large drop, so the benefit of the medicine itself is the gap between the groups, not the headline percentage alone.
The trial also scored how severe flashes were. At week 12 both doses came out ahead of placebo on that score, and in this trial the 45 mg group's difference was the larger one on both measures. Frequency is the easier measure to judge, because it is counted in flashes a day.
Our hot flashes page covers the symptom in more depth. Some women will find the gap from placebo a meaningful change in their day; for others, having a non-hormonal route at all matters more. Both views are reasonable.
How is fezolinetant taken, and what monitoring is involved?
Fezolinetant is taken as one tablet a day. The trial tested 30 mg and 45 mg, each for 12 weeks, and your prescriber will advise on the dose.
Liver blood tests are part of taking this medicine. According to the FDA's 2024 safety communication, a test is required before starting, then monthly for the first 3 months, then again at months 6 and 9. Your primary care provider, or your GP in the UK, can explain how the tests are arranged, and it is worth mentioning any past liver problems.
What did the studies show, and what is still unclear?
The large majority of women in the 12-week trial had no notable rise in liver enzymes. ALT, one of the enzymes in a liver blood test, rose above 3 times the upper limit of normal in 1.2% of women on 30 mg, 1.8% on 45 mg and 0.6% on placebo, and six participants overall had ALT or AST above that level. The FDA's boxed warning came later and describes the liver injury as rare; the blood tests are there so that any change shows up on a result.
Because the trial lasted 12 weeks, it shows short-term benefit and safety, and it is reasonable to ask a prescriber what is known beyond that. It also tested fezolinetant against placebo, so it cannot tell us how the medicine compares head to head with SSRIs, SNRIs, gabapentin or CBT.
Fezolinetant and non-hormonal options by life stage
| Stage | Figure | Why | Read more |
|---|---|---|---|
| Childhood | No use at this stage | Fezolinetant's only use is moderate to severe hot flashes caused by menopause, so it has no role in childhood. | What changes |
| Puberty | No trial data below age 40 | The fezolinetant trial behind this page's figures included no teenagers. | What changes |
| Reproductive years | Tested from age 40 upward | The trial's youngest participants were 40, and fezolinetant is for flashes caused by menopause, not for cycle-related symptoms. | What changes |
| Perimenopause | Trial age range: 40 to 65 years | The trial analysed 500 women in this range. | What changes |
| Menopause | -58.6% (30 mg) and -64.3% (45 mg) vs -45.4% placebo | Change in hot flash frequency at week 12; mean age about 54. | What changes |
| Postmenopause | Trial upper age 65; trial length 12 weeks | The trial included women up to 65 but ran for 12 weeks, so longer use in the years after menopause is a question for a prescriber; the liver tests run to month 9. | What changes |
Guidance by country
Facts
Common questions
What is fezolinetant used for?
Its one use is hot flashes caused by menopause that are moderate to severe, which medical documents call vasomotor symptoms and UK usage calls hot flushes and night sweats. The people to ask about a prescription are a primary care provider or OB-GYN in the US, or a GP in the UK.
When will fezolinetant be available in the UK?
It already is. Private prescriptions have been possible since 5 January 2024 under an MHRA licence for menopausal hot flushes and night sweats, and the 2026 NICE recommendation covers women for whom HRT isn't suitable or wanted. If cost matters, it is worth asking a GP about an NHS prescription before paying privately.
What are the side effects of fezolinetant?
The 12-week trial recorded no serious drug-related events and no deaths. Any adverse event was reported by 40.4% of women on 30 mg, 35.9% on 45 mg and 32.3% on placebo, so the rates sat close to those on a dummy tablet, with headache the most common. Serious events were 1.8%, 1.2% and 0%.
Why did the FDA add a boxed warning to fezolinetant?
The FDA first issued a safety communication on 12 September 2024, then on 16 December 2024 added a Boxed Warning, its most prominent kind, for liver injury it describes as rare but serious. The blood test plan follows from it, and a prescriber can talk through what it means for you before you decide.
What does the NHS offer for hot flushes if I can't take HRT?
The NHS first-line non-hormonal route is CBT. If that does not help, a doctor may suggest clonidine or an antidepressant, and antidepressants may also be offered for low mood or anxiety. Red clover and black cohosh have very little evidence on effectiveness or safety.
Next steps
If hot flashes are affecting your days or nights, a good place to start is a short note of how often they happen and how much they bother you, then a conversation with your primary care provider or GP. You might ask whether HRT, fezolinetant, an SSRI or SNRI, gabapentin or CBT fits your health history, and how the blood tests would be arranged. If any of the red flags on this page applies to you, it is worth booking a visit sooner. Some women will put a non-hormonal tablet first and accept the blood tests that come with it; others will prefer HRT, CBT or waiting to see how symptoms settle. This is not one size fits all, and which of those fits is yours to decide.
See a doctor promptly if you have
- Any bleeding 12 months or more after your last period
- Symptoms that are getting worse, whether or not you are on treatment
- While taking fezolinetant: unusual tiredness, nausea or vomiting, unusual itching, light-colored stools or dark urine, yellowing of the skin or eyes (jaundice), swelling of the abdomen, or pain in the upper right abdomen. The FDA advises stopping the tablet and contacting your prescriber.
Sources
The guidelines and studies this page draws on.
- FDA Drug Safety Communication: FDA adds warning about rare occurrence of serious liver injury with use of fezolinetant for hot flashes due to menopause, U.S. Food and Drug Administration (2024)
- Neal-Perry et al.: phase 3 trial of fezolinetant for hot flashes, Journal of Clinical Endocrinology & Metabolism / PubMed Central (2023)
- NICE TA1143, 2026: Fezolinetant for vasomotor symptoms of menopause, NICE (2026)
- NHS: Menopause, Treatment, NHS (England) (2026)
- Non-hormonal treatment for menopause vasomotor symptoms approved for use in the UK, The Pharmaceutical Journal (2023)