Fezolinetant
Fezolinetant (Veozah) is the first non-hormonal, non-antidepressant medication FDA-approved specifically for moderate to severe menopause hot flashes.
How it works
Hot flashes arise when estrogen loss disrupts the thermoregulatory neurons of the hypothalamus. A population of neurons called KNDy neurons — which release neurokinin B (NKB) — becomes overactive without estrogen's moderating signal, triggering the heat-dissipation response that produces hot flashes. Fezolinetant selectively blocks the NK3 receptor that NKB activates, quieting this misfiring circuit without using hormones or affecting serotonin. The SKYLIGHT 1 and SKYLIGHT 2 trials (published in JAMA 2023) showed roughly 60% reduction in hot flash frequency at 12 weeks, compared to roughly 45% with placebo — with meaningful separation appearing by week 4.
Fezolinetant is taken daily and requires liver function monitoring before starting and periodically during treatment; it is contraindicated in people with moderate to severe hepatic impairment and in those taking CYP1A2 inhibitors such as fluvoxamine or ciprofloxacin. It is an option for people who cannot use hormone therapy — including breast cancer survivors on tamoxifen — though long-term data beyond the 12-week trial window is still accumulating.
How to track Fezolinetant
- Hot flash frequency: total count per day and per week — the primary endpoint used in the SKYLIGHT trials, and the clearest signal of whether the drug is working.
- Hot flash severity on a mild/moderate/severe scale — frequency alone doesn't capture how disruptive episodes are.
- Night sweats separately from daytime hot flashes, since sleep disruption has its own downstream effects on mood, cognition, and daytime function.
- Time to first meaningful response — trial data shows separation from placebo by week 4; tracking week-by-week frequency reveals whether your trajectory is typical.
- Liver function test dates and results — fezolinetant requires hepatic monitoring; logging test dates keeps the monitoring schedule visible.
- Any concurrent medications that are CYP1A2 inhibitors — this interaction is clinically significant and worth flagging in your log before any new prescription.
- Log hot flash frequency for one to two weeks before starting to establish a genuine baseline — without one, you can't measure response objectively at week 4 or week 12.
- Use the same severity scale (mild/moderate/severe) consistently; the SKYLIGHT trials used this exact categorization, so your log mirrors the clinical measurement your physician is looking for.
- Track night sweats as a separate entry from daytime hot flashes — they affect different things (sleep vs. daytime function) and may respond on different timelines.
- Mark your liver function test dates in your log alongside symptom data — monitoring compliance and symptom response belong in the same record.
- At week 4 and week 12, compare weekly averages to your pre-treatment baseline. Those are the checkpoints the trial protocol used; your physician will likely use them too.
Questions to ask your physician
- My pre-treatment baseline was [X] hot flashes per day. At week [4/8/12] on fezolinetant, my current daily average is [Y]. Is that response trajectory consistent with the SKYLIGHT trial data?
- I've been logging severity as [mild/moderate/severe] — the distribution has shifted from [pre-treatment pattern] to [current pattern]. Does that change the picture of how well it's working?
- My night sweat log shows [X] episodes per week, which is [better/unchanged] from baseline. Is vasomotor improvement expected to be uniform across day and night?
- My liver function was tested on [date]. When does the monitoring schedule call for the next check, and should I log any symptoms in the meantime?