Fezolinetant (Veozah) for hot flashes

Fezolinetant (brand name Veozah) is a once-daily, non-hormonal pill approved by the FDA in May 2023 for moderate to severe hot flashes and night sweats due to menopause. In two 12-week trials it reduced daily hot flashes by roughly 2.5 more episodes than placebo, with effects visible in the first week. The trade-offs are a boxed warning for rare liver injury, a schedule of blood tests, and a high list price.

What it is and how it works

Hot flashes originate in the hypothalamus, where a group of neurons (called KNDy neurons) releases a signaling molecule, neurokinin B. Estrogen normally restrains these neurons. As estrogen falls across the menopause transition, they become overactive, flooding the nearby temperature control center with neurokinin B and triggering a flash.

Fezolinetant blocks the receptor that neurokinin B binds to (the neurokinin 3 receptor). That directly interrupts the mechanism, without adding any hormone. The Menopause Society’s 2023 position statement gives fezolinetant its highest (Level I) recommendation and notes it is one of only a few non-hormonal drugs FDA-approved for this purpose, alongside paroxetine 7.5 mg. A related drug, elinzanetant, was approved in October 2025.

What the evidence shows

Two nearly identical phase 3 trials, SKYLIGHT 1 (published in The Lancet) and SKYLIGHT 2 (Journal of Clinical Endocrinology and Metabolism), enrolled women aged 40 to 65 who were having at least seven moderate to severe hot flashes a day. Each randomized about 500 women to placebo, fezolinetant 30 mg, or 45 mg for 12 weeks, then continued active drug for 40 more weeks.

According to the FDA label’s pooled tables:

• In Trial 1, women started at 10.4 flashes a day. By week 12, the 45 mg group fell by 6.4 a day versus 3.9 for placebo, a difference of 2.6 (95% CI 1.7 to 3.4).
• In Trial 2, women started at 11.8 a day. By week 12, the 45 mg group fell by 7.5 versus 5.0 for placebo, a difference of 2.5 (95% CI 1.5 to 3.6).
• Severity also dropped significantly at weeks 4 and 12, by 0.2 to 0.3 points more than placebo on the trials’ severity scale (baseline average 2.4).

Two things are worth noticing. First, the placebo groups improved a lot (by 4 to 5 flashes a day), which is typical in hot flash trials. Second, the drug’s added benefit, about 2.5 fewer flashes a day, met the FDA’s threshold for a clinically meaningful difference (2 or more over 24 hours). Improvements appeared after one week and were maintained through 52 weeks in the open extension.

This is strong evidence for the 12-week placebo-controlled period. Long-term data beyond one year, and data on quality of life, mood, and sexual function, are more limited, as the SKYLIGHT 1 authors acknowledge.

Dose, how it is taken, time to effect

The approved dose is one 45 mg tablet once a day, with or without food, at about the same time each day. There is no titration. Most women notice change within the first one to two weeks; trials measured the primary effect at weeks 4 and 12.

Before you start, your clinician must order liver blood tests (ALT, AST, alkaline phosphatase, and bilirubin). The label says not to start if ALT or AST is at or above twice the upper limit of normal or if bilirubin is elevated. While on the drug, tests are repeated monthly for the first three months, then at months 6 and 9, and any time symptoms suggest a liver problem.

Side effects and who should avoid it

In the 52-week safety trial reported in the label, the most common side effects occurring in at least 2% of women and more often than placebo were abdominal pain (4.3% vs 2.1%), diarrhea (3.9% vs 2.6%), insomnia (3.9% vs 1.8%), and back pain (3.0% vs 2.1%). In SKYLIGHT 1, overall adverse events during the first 12 weeks were no more common with fezolinetant (37% to 43%) than placebo (45%).

Liver. Across three trials, liver enzyme elevations greater than three times normal occurred in 2.3% of women on fezolinetant versus 0.9% on placebo. In the trials these were asymptomatic and resolved. After approval, however, a case of serious drug-induced liver injury with jaundice occurred within 40 days of starting, which led the FDA to add a boxed warning on December 16, 2024. The injury resolved after stopping the drug. The warning is about a rare event, but it is why the lab schedule exists and why you should know the symptoms listed in the FAQ above.

Do not use if you have known cirrhosis, severe kidney impairment or end-stage kidney disease, or take any CYP1A2 inhibitor. Fezolinetant is cleared mainly by the CYP1A2 enzyme; the strong inhibitor fluvoxamine raised drug exposure by 840%, and even the weak inhibitor cimetidine (an over-the-counter heartburn drug) doubled it. Smoking, which speeds up CYP1A2, did not meaningfully change exposure. Bring a full medication list, including over-the-counter products, to your appointment.

The pivotal trials enrolled postmenopausal women aged 40 to 65 from the general population. If you are being treated for breast cancer, ask your oncologist whether it fits your plan.

Cost and insurance in the US

As of March 2026, the cash price for a 30-day supply of 45 mg tablets averages about $778 at US pharmacies, according to SingleCare. The manufacturer has stated that roughly 64% of commercially insured people have a plan that covers it, though it is often placed on a non-preferred tier with higher copays and prior authorization. Medicare coverage has been limited to select plans, and Medicaid coverage varies by state.

A manufacturer savings program for commercially insured patients caps benefits at $4,000 per year, and a patient assistance program exists for people without insurance. The required liver tests are an additional cost to ask about.

How it compares with other options

Option	Reduction vs placebo (approximate)	Main cautions	Generic available
Fezolinetant 45 mg	About 2.5 fewer flashes/day at week 12	Liver tests, CYP1A2 interactions	No (about $780/month cash)
Elinzanetant 120 mg	About 3.2 fewer flashes/day at week 12 (OASIS 1 and 2)	Newest drug, least long-term data	No
Paroxetine 7.5 mg	0.9 to 1.7 fewer flashes/day at week 12 (median)	Not with tamoxifen; SSRI warnings	Paroxetine yes
Venlafaxine 75 mg	About 1.8 fewer flashes/day at week 8	Nausea, dry mouth	Yes
Gabapentin 900 to 2,400 mg	35 to 38% more than placebo in pooled trials	Drowsiness, dizziness	Yes
Low-dose oral estradiol	About 2.3 fewer flashes/day at week 8	Hormone contraindications	Yes

No trial has compared fezolinetant head-to-head with these alternatives. The Menopause Society notes that hormone therapy remains the most effective treatment for women who can take it. Fezolinetant’s niche is women who cannot or prefer not to use estrogen and who want a drug built for hot flashes rather than borrowed from another condition.

Questions for your clinician

• Am I a candidate for hormone therapy instead, and how would the two compare for me?
• Do any of my medications or supplements inhibit CYP1A2?
• What are my baseline liver results, and how will we schedule the follow-up tests?
• Does my plan cover Veozah, and does it need prior authorization or a trial of another drug first?
• How will we judge success at 4 and 12 weeks, and what is plan B?

If you need help finding someone comfortable prescribing newer menopause drugs, see how to find a menopause specialist or browse OB-GYNs near you.