Veozah (fezolinetant) treats menopausal hot flashes by blocking a specific chemical signal in the brain’s temperature control center, without using hormones. It’s a once-daily 45 mg tablet that can start reducing symptoms within the first week of treatment.
To understand why this matters, it helps to know what’s actually happening in your brain when a hot flash strikes, and how Veozah intervenes at a very precise point in that process.
What Causes Hot Flashes in the Brain
Your brain has a built-in thermostat located in the hypothalamus. This region constantly monitors your body temperature and triggers cooling responses (like sweating and flushing) when it thinks you’re overheating. In menopausal women, this thermostat becomes unstable.
The problem traces back to a specific group of nerve cells called KNDy neurons. These neurons sit in the hypothalamus and connect directly to the thermoregulatory center. They respond to estrogen, and when estrogen levels drop during menopause, the neurons ramp up production of a signaling molecule called neurokinin B. That surge of neurokinin B overstimulates the temperature control center, essentially tricking your brain into thinking your body is too warm. The result: blood vessels near the skin dilate, you start sweating, your heart rate increases, and you experience the sudden wave of heat that defines a hot flash.
Postmortem studies of postmenopausal women have confirmed that neurokinin B activity is markedly increased in the hypothalamus compared to premenopausal women, and this increase tracks closely with estrogen loss.
How Veozah Targets the Problem
Veozah works by blocking the receptor that neurokinin B binds to on KNDy neurons, called the NK3 receptor. By occupying that receptor, fezolinetant prevents neurokinin B from delivering its overactive signal to the thermoregulatory center. The temperature control system calms down, and the false alarms that trigger hot flashes become less frequent and less intense.
This is a fundamentally different approach from hormone replacement therapy. Estrogen therapy works by restoring the hormone that originally kept KNDy neurons in check, which addresses hot flashes but also affects the entire body (breast tissue, uterine lining, cardiovascular system, bone). Veozah skips the hormonal system entirely and instead intercepts the downstream signal that’s directly responsible for thermoregulatory disruption. It doesn’t raise or lower any hormone levels.
That distinction makes Veozah relevant for women who can’t take estrogen due to a history of breast cancer, blood clots, or cardiovascular risk, as well as those who simply prefer to avoid hormonal treatment.
How Quickly It Works
In the SKYLIGHT 1 clinical trial, women taking Veozah 45 mg noticed improvement within the first week of treatment. By week 4, hot flash frequency dropped significantly compared to placebo, with roughly two fewer moderate-to-severe episodes per day. By week 12, that reduction grew further. Severity scores also improved at both time points.
The benefits held up over the long term. In the trial’s 40-week extension phase (52 weeks total), improvements in both frequency and severity of hot flashes were maintained. The study population was racially and ethnically diverse, which strengthens confidence that the results apply broadly.
Taking Veozah
The FDA-approved dose is one 45 mg tablet taken once daily, with or without food. There’s no need to time it around meals or adjust based on body weight.
One important limitation: Veozah cannot be taken with any medication that inhibits a liver enzyme called CYP1A2, because your body relies on that enzyme to break down the drug. When CYP1A2 is blocked, fezolinetant accumulates to potentially dangerous levels. A strong inhibitor like fluvoxamine (an antidepressant) increased blood levels of fezolinetant by 840%. Even weak inhibitors like cimetidine (an older heartburn medication) doubled the drug’s exposure. This contraindication covers weak, moderate, and strong CYP1A2 inhibitors alike, so your prescriber will need to review your full medication list before starting treatment.
Liver Monitoring Requirements
Veozah carries a specific concern about liver health that requires blood testing on a set schedule. Before starting treatment, you’ll need baseline liver function tests measuring enzymes (ALT and AST) and bilirubin. If your ALT or AST levels are already at or above twice the upper limit of normal, or your total bilirubin is similarly elevated, Veozah should not be started.
Once you begin, the monitoring schedule is:
- Monthly for the first 3 months
- At 6 months after starting
- At 9 months after starting
If liver enzymes climb above five times the normal limit, or above three times normal with elevated bilirubin, the medication needs to be stopped. In clinical trials, 2.3% of women on Veozah experienced elevated liver enzymes compared to 0.8% on placebo. This is relatively uncommon, but the monitoring schedule exists because liver injury can be serious if caught late.
Common Side Effects
Most women tolerate Veozah well. In the 52-week clinical trial, the side effects that occurred more often with Veozah than with placebo were modest in both frequency and severity:
- Abdominal pain: 4.3% vs. 2.1% on placebo
- Diarrhea: 3.9% vs. 2.6%
- Insomnia: 3.9% vs. 1.8%
- Back pain: 3.0% vs. 2.1%
- Hot flush: 2.5% vs. 1.6%
- Liver enzyme elevation: 2.3% vs. 0.8%
The gap between drug and placebo is relatively small for most of these, which means many of these symptoms overlap with what women experience during menopause regardless of treatment. The insomnia finding is worth noting since poor sleep is already common during menopause, though only about 2% more women reported it on Veozah compared to placebo.
Why a Non-Hormonal Option Matters
For decades, hormone therapy was essentially the only highly effective treatment for hot flashes. Other non-hormonal options (certain antidepressants, gabapentin) were used off-label with modest results and their own side effect profiles. Veozah represents the first medication designed from the ground up to target the specific brain pathway responsible for menopausal hot flashes without involving hormones at all.
By working at the level of a single receptor type in the hypothalamus, it avoids the systemic effects of estrogen while still addressing the root neurological cause rather than just masking symptoms. For women who experience frequent, disruptive hot flashes and either can’t or don’t want to use hormones, that precision is what makes this mechanism meaningfully different from what came before.