If hot flashes are wrecking your sleep and you cannot or do not want to use hormone therapy, fezolinetant is worth understanding. In SKYLIGHT 1, women taking fezolinetant 45 mg had 2.07 fewer moderate to severe hot flashes per day than placebo at week 4 and 2.55 fewer per day at week 12. [1]
That is real evidence. It is not a claim that fezolinetant beats hormone replacement therapy.
What fezolinetant is actually for
Fezolinetant is a nonhormonal prescription medication for moderate to severe vasomotor symptoms due to menopause. It works through neurokinin 3 receptor antagonism rather than estrogen replacement. [4]
That distinction is useful for women who are not good candidates for systemic estrogen or who strongly prefer a nonhormonal route. It also narrows the promise. Fezolinetant is a hot-flash and night-sweat treatment. It is not a treatment for vaginal dryness, painful sex from genitourinary syndrome of menopause, bone loss, low desire, weight gain, or every symptom that shows up during midlife.
The broader hormone replacement therapy evidence review covers the hormone-therapy decision separately.
What the phase 3 trials found
SKYLIGHT 1 randomized women aged 40 to 65 who averaged at least 7 moderate to severe hot flashes per day. At week 4, fezolinetant 45 mg reduced frequency versus placebo by 2.07 episodes per day. At week 12, the difference was 2.55 episodes per day. Improvements were observed after 1 week and maintained over 52 weeks. [1]
SKYLIGHT 2 was similar. At week 4, fezolinetant 45 mg reduced frequency versus placebo by 2.55 episodes per day. At week 12, the difference was 2.53 episodes per day. Serious treatment-emergent adverse events were infrequent in the 12-week placebo-controlled period. [2]
The trial result is measured in daily symptom counts. If a woman is having 8 to 10 disruptive episodes a day, a reduction of about 2 to 3 more episodes than placebo can be meaningful, especially when sleep is the main problem.
Why the liver warning changed the decision
The current VEOZAH label includes a boxed warning for risks of hepatotoxicity. It says hepatic laboratory tests should be done before starting treatment, monthly for the first 3 months, and again at months 6 and 9. The label also says not to start VEOZAH when aminotransferases are at least 2 times the upper limit of normal or total bilirubin is at least 2 times the upper limit of normal. [4]
That does not mean every patient should avoid it. It does mean fezolinetant should not be presented as a casual supplement-like hot-flash option. The safety workflow is part of the product.
Red flags before choosing fezolinetant
The liver warning changes the practical decision. Fezolinetant can be a strong fit for some women who want or need a nonhormonal route for moderate to severe hot flashes, but it is a poor fit when the monitoring plan is vague.
| Red flag or pause point | Why it matters |
|---|---|
| Known cirrhosis | VEOZAH is contraindicated in women with known cirrhosis. [4] |
| Severe renal impairment or end-stage renal disease | The label lists severe renal impairment and ESRD as contraindications. [4] |
| Concomitant CYP1A2 inhibitor use | CYP1A2 inhibitors are contraindicated because they can raise fezolinetant exposure. [4] |
| ALT or AST at least 2 times ULN, or total bilirubin at least 2 times ULN before treatment | The label says not to start VEOZAH at these thresholds. [4] |
| New fatigue, decreased appetite, nausea, vomiting, itching, jaundice, pale stool, dark urine, or abdominal pain | The label says to stop immediately and seek medical attention with liver labs if symptoms suggest liver injury. [4] |
| Symptoms are mostly vaginal dryness, painful sex, recurrent urinary symptoms, bone loss, mood, libido, or weight | Fezolinetant targets vasomotor symptoms, so another menopause route may fit the main problem better. |
How it compares with hormone therapy in a real visit
| Question | Fezolinetant route | hormone replacement therapy route |
|---|---|---|
| Main symptom target | Moderate to severe hot flashes and night sweats. [4] | Hot flashes and night sweats, with other menopause targets depending on formulation. [5] |
| Hormone exposure | Nonhormonal. | Estrogen with or without progestogen depending on uterus status and route. |
| Trial comparison | Placebo-controlled SKYLIGHT trials, not direct hormone replacement therapy comparisons. [1] [2] | Hormone therapy has a separate evidence and risk-benefit framework. [5] |
| Monitoring emphasis | Liver labs before treatment and during months 1, 2, 3, 6, and 9. [4] | Uterus status, clot/stroke risk, breast cancer history, blood pressure, dose, route, and timing. |
| Best-fit conversation | Women who need or prefer a nonhormonal option for vasomotor symptoms. | Women whose symptom pattern and risk profile make hormone therapy appropriate. |
The 2023 North American Menopause Society nonhormone statement lists feasible nonhormonal options for vasomotor symptoms, including prescription options and behavioral approaches, while separating them from therapies with insufficient or negative evidence. [3] That is the right structure: match the symptom, then match the route.
The current nonhormonal prescription category is also broader than it was when fezolinetant first launched. Elinzanetant is another FDA-labeled neurokinin-pathway option for moderate to severe vasomotor symptoms due to menopause. Its 2025 label describes baseline hepatic testing and follow-up testing at 3 months, and says it is not recommended in moderate to severe hepatic impairment. [6] That does not make elinzanetant and fezolinetant interchangeable. It means a clinician now has to compare nonhormonal options, not only compare one nonhormonal drug with hormone replacement therapy.
| Decision point | Fezolinetant may fit better when | hormone replacement therapy may fit better when | Another route may fit better when |
|---|---|---|---|
| Main problem | Moderate to severe hot flashes or night sweats are the dominant symptom. | Hot flashes overlap with genitourinary syndrome of menopause, bone-risk prevention, or broader hormone-responsive symptoms and the risk profile fits. | Symptoms are driven by sleep apnea, mood disorder, medication effects, thyroid disease, vaginal symptoms, or another diagnosis. |
| Hormone preference or contraindication | A nonhormonal prescription route is desired or systemic estrogen is not appropriate. | Hormone therapy is desired, uterus status and risk factors are reviewed, and benefit-risk is favorable. | selective serotonin reuptake inhibitor or serotonin-norepinephrine reuptake inhibitor, gabapentin, oxybutynin, elinzanetant, cognitive behavioral therapy, or another route fits better. |
| Monitoring capacity | Baseline and follow-up liver testing is realistic. | hormone replacement therapy risk review and follow-up are realistic. | The patient cannot complete the required monitoring or has contraindications to both categories. |
| Evidence expectation | The goal is fewer daily vasomotor episodes versus placebo, not whole-body menopause treatment. | The goal matches hormone replacement therapy's evidence base and labeled/formulation-specific use. | The goal is sleep, mood, genitourinary syndrome of menopause, libido, weight, or bone health rather than hot flashes. |
What the evidence supports
Fezolinetant is an FDA-approved, nonhormonal prescription option for moderate to severe hot flashes due to menopause, supported by phase 3 placebo-controlled trials. The current label requires liver testing, and the drug should not be positioned as a head-to-head replacement for hormone therapy.
The useful patient-facing question is not "hormone replacement therapy or fezolinetant?" It is "What symptom are we treating, what risks need screening, and what monitoring does this route require?"
Bottom line
Fezolinetant is a nonhormonal, prescription hot-flash option with placebo-controlled phase 3 evidence and liver-monitoring requirements. Hormone replacement therapy is a separate hormone-therapy route with a different benefit-risk framework.
The decision should start with the symptom target and safety screen, not with a blanket claim that one route replaces the other.
What to ask a clinician
Ask:
- Are my symptoms moderate-to-severe vasomotor symptoms, or is another sleep problem also present?
- Am I a better candidate for nonhormonal therapy, hormone therapy, or another option?
- What liver tests are required before and during fezolinetant?
- Which symptoms or lab changes mean the medicine should stop?
- If hot flashes improve but sleep, mood, vaginal symptoms, or weight concerns remain, what is the separate plan?
- If I want a nonhormonal option, how do fezolinetant, elinzanetant, antidepressant-class options, gabapentin, and oxybutynin compare for my history?
Related reading:
- Gabapentin for Hot Flashes After Menopause.
- Hormone Therapy After Menopause.
- How Long Do Hot Flashes Last? Seven Years Is Not Rare.
References
[1] Lederman S, Ottery FD, Cano A, et al. Fezolinetant for treatment of moderate-to-severe vasomotor symptoms associated with menopause (SKYLIGHT 1): a phase 3 randomised controlled study. Lancet. 2023;401(10382):1091-1102. doi:10.1016/s0140-6736(23)00085-5 https://pubmed.ncbi.nlm.nih.gov/36924778/
[2] Johnson KA, Martin N, Nappi RE, et al. Efficacy and Safety of Fezolinetant in Moderate to Severe Vasomotor Symptoms Associated With Menopause: A Phase 3 RCT. J Clin Endocrinol Metab. 2023;108(8):1981-1997. doi:10.1210/clinem/dgad058 https://pubmed.ncbi.nlm.nih.gov/36734148/
[3] New Collective Author. The 2023 nonhormone therapy position statement of The North American Menopause Society. Menopause. 2023;30(6):573-590. doi:10.1097/gme.0000000000002200 https://pubmed.ncbi.nlm.nih.gov/37252752/
[4] DailyMed. VEOZAH (fezolinetant) prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cae9f798-24f9-4580-a4fc-e6c710cbda3c
[5] “The 2022 Hormone Therapy Position Statement of The North American Menopause Society” Advisory Panel. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause. 2022;29(7):767-794. doi:10.1097/gme.0000000000002028 https://pubmed.ncbi.nlm.nih.gov/35797481/
[6] FDA. LYNKUET (elinzanetant) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/219469s000lbl.pdf