Can I Take Folate with Veozah (Fezolinetant)?

What Is Fezolinetant and Who Is It For?

Fezolinetant is the first FDA-approved non-hormonal, non-antidepressant prescription treatment for moderate-to-severe vasomotor symptoms (VMS) caused by menopause. The FDA approved fezolinetant in May 2023 for this indication at a dose of 45 mg once daily. It works by blocking neurokinin 3 (NK3) receptors in the hypothalamus, quieting the KNDy neuron signaling that triggers hot flashes when estrogen declines.

How It Differs From Hormone Therapy

Fezolinetant carries no estrogen, no progestogen, and no androgenic activity. That matters for women who cannot or prefer not to use menopausal hormone therapy (MHT), including survivors of estrogen-receptor-positive breast cancer, women with a personal history of venous thromboembolism, and those who simply want a non-hormonal path. The SKYLIGHT 1 and SKYLIGHT 2 phase 3 trials showed fezolinetant reduced moderate-to-severe hot flash frequency by approximately 60% at 12 weeks compared with 45% for placebo.

Which Life Stages Are Affected?

Fezolinetant is labeled for menopausal VMS, meaning it is relevant for:

• Perimenopause: Women in late perimenopause who already have irregular cycles and significant hot flashes. Hormonal fluctuation is extreme in this stage and hot flashes may be most severe.
• Postmenopause: The primary studied population in SKYLIGHT trials; median age was 54 years.
• Surgical menopause: Women who had bilateral oophorectomy and experience acute, often severe VMS.

It is not approved for premenopausal women or for any indication in reproductive-age women outside of menopause-related VMS.

What Is Folate and Why Do Perimenopausal Women Take It?

Folate is the umbrella term for vitamin B9 in all its forms. Folic acid is the synthetic oxidized form used in supplements and fortified foods. Methylfolate (5-MTHF) is the biologically active reduced form that crosses the blood-brain barrier and enters the methylation cycle directly.

Why Women in Midlife Still Need Folate

Many women associate folate only with pregnancy. The truth is more specific:

• MTHFR variants: Roughly 10 to 15% of people of Northern European descent carry the homozygous MTHFR C677T variant, which reduces enzyme activity by up to 70% and impairs conversion of folic acid to active methylfolate. For these women, methylfolate is more appropriate regardless of age or reproductive status.
• Cardiovascular protection: Folate participates in homocysteine remethylation. Elevated homocysteine is associated with increased cardiovascular risk, and postmenopausal women have higher mean homocysteine levels than premenopausal women of the same age, likely because estrogen facilitates homocysteine metabolism.
• Mood and cognitive function: Folate is a cofactor in serotonin and dopamine synthesis. Some women in perimenopause use methylfolate to support mood during the estrogen dip, though evidence for this specific use is limited and largely extrapolated from depression trials rather than directly studied in perimenopausal cohorts. The honest assessment: the mood data for folate in perimenopause is thin and should not be oversold.
• Bone health: Hyperhomocysteinemia impairs collagen cross-linking in bone matrix. A 2004 study in the New England Journal of Medicine showed elevated homocysteine was independently associated with hip fracture risk in older men and women. Folate-mediated homocysteine lowering may therefore have indirect bone benefits, though this remains an area of ongoing study.

Typical Doses in This Population

| Form | Common Dose | Bioavailability Note | |---|---|---| | Folic acid (synthetic) | 400 to 800 mcg/day | Requires DHFR enzyme conversion; impaired in MTHFR variants | | Methylfolate (5-MTHF) | 400 to 1000 mcg/day | Directly bioavailable; preferred if MTHFR positive | | Folinic acid (leucovorin) | Rarely used in general population | Prescribed form; bypasses MTHFR but not as bioavailable as 5-MTHF |

Does Folate Interact With Fezolinetant?

The short answer: no clinically meaningful interaction has been identified. Here is the mechanistic reasoning for why.

Fezolinetant's Metabolic Pathway

Fezolinetant is metabolized primarily by CYP1A2 in the liver, with minor contributions from CYP3A4. The FDA prescribing information explicitly contraindicates fezolinetant with strong CYP1A2 inhibitors (for example, fluvoxamine, ciprofloxacin) because they can raise fezolinetant plasma concentrations substantially.

Folate does not inhibit or induce CYP1A2. It does not bind to CYP3A4 in a clinically relevant way. Folate is not a P-glycoprotein substrate that would compete at absorption sites. Based on the mechanism of metabolism, a pharmacokinetic drug-supplement interaction is not expected and none has been reported in the clinical trial safety database for SKYLIGHT 1, SKYLIGHT 2, or the 52-week SKYLIGHT 4 extension.

What About the Methylation Connection?

This is the question that generates the most confusion. Fezolinetant is not a folate-dependent drug. It does not require methylation for activation or deactivation. The methylation cycle that folate supports (converting homocysteine to methionine, generating S-adenosylmethionine) does not intersect with NK3 receptor antagonism at any known step.

The confusion likely arises because folate is often discussed alongside anticonvulsants (carbamazepine, valproate, phenytoin), which deplete folate through enzyme induction and increase neural tube defect risk in pregnancy. Fezolinetant is not an anticonvulsant, does not induce folate-depleting enzymes, and has no mechanism by which it would lower folate levels.

The One Area to Watch: Hepatotoxicity Overlap

Both fezolinetant and very high-dose folate supplements (above 5 mg/day, a prescription dose used in some genetic conditions or pregnancy complications) are processed hepatically. Fezolinetant carries an FDA boxed-adjacent warning requiring liver function testing at baseline, 3 months, and 6 months because SKYLIGHT 4 showed transaminase elevations in approximately 2.3% of women on fezolinetant versus 0.3% on placebo. Standard over-the-counter folate doses of 400 to 800 mcg daily are not hepatotoxic. Prescription-dose folic acid at 1 to 5 mg/day has also not been associated with liver injury at normal kidney function. The overlap concern is theoretical for doses above 5 mg, not for the standard supplemental range most women use.

A practical framework for evaluating any supplement alongside fezolinetant:

1. Does the supplement inhibit or induce CYP1A2? If yes, it is a real concern.
2. Does the supplement carry independent hepatotoxic risk? If yes, tell your prescriber.
3. Does the supplement affect NK3 signaling? No known supplement does.
4. Does the supplement affect folate or B12 status in a way that changes your overall nutrient picture? Worth tracking but not a fezolinetant-specific concern.

Folate fails criteria 1 and 2 at standard doses. It is category 4, manageable at the population level.

MTHFR, Folate Form, and the Perimenopausal Woman

MTHFR status matters more to you than to any drug interaction database. Here is why it deserves its own section.

Should You Be Taking Methylfolate Instead of Folic Acid?

If you have a confirmed homozygous MTHFR C677T or A1298C variant, folic acid from supplements may accumulate as unmetabolized folic acid in the blood rather than converting to active 5-MTHF. A 2019 review in Nutrients found that unmetabolized folic acid may paradoxically interfere with folate receptor binding at high doses. This does not interact with fezolinetant. It does mean your folate supplementation strategy should be individualized.

Testing and Monitoring

Your clinician can order:

• MTHFR genotyping (blood test, often covered with clinical indication)
• RBC folate (reflects tissue stores more accurately than serum folate)
• Homocysteine level (functional marker of methylation adequacy)

If you are on fezolinetant and your clinician is already doing liver function tests at 3 and 6 months, that is a reasonable window to also check RBC folate and homocysteine if you have MTHFR concerns. Combining monitoring visits reduces out-of-pocket burden.

Pregnancy, Lactation, and Contraception

Fezolinetant is contraindicated in pregnancy. This is not a soft caution. The FDA prescribing label states that fezolinetant may cause fetal harm based on animal reproductive toxicity data. No adequate human data exist in pregnant women. In rat studies, fezolinetant caused embryo-fetal death and structural malformations at exposures below the human therapeutic dose.

Who Needs to Think About This?

Fezolinetant is labeled for menopausal VMS, so most women starting it are peri- or postmenopausal. However:

• Late perimenopause: Ovulation can still occur sporadically even when cycles are irregular. A woman aged 48 with hot flashes is not necessarily infertile. Spontaneous pregnancy in perimenopause, while uncommon, is documented. The American College of Obstetricians and Gynecologists (ACOG) recommends continuing contraception until 12 months of amenorrhea in women under 50 and until 24 months in women under 45.
• Women under 45 with premature ovarian insufficiency (POI): POI-related hot flashes are sometimes treated off-label with non-hormonal agents. These women may retain fertility potential and must use reliable contraception while on fezolinetant.

What Folate Adds to the Pregnancy Discussion

If there is any chance of pregnancy while on fezolinetant, stop fezolinetant immediately and consult your prescriber. Folate, on the other hand, is not just safe in pregnancy but essential. The CDC recommends 400 mcg of folic acid daily for all women of reproductive potential, and 4 mg/day for women with a prior neural tube defect-affected pregnancy. Folate does not need to be stopped if pregnancy occurs; fezolinetant does.

Lactation

There are no human data on fezolinetant transfer into breast milk. Given that fezolinetant is a drug indicated for menopausal women, lactation is an uncommon but not impossible scenario (for example, late perimenopause, breastfeeding a young child while experiencing menopausal transition). The prescribing information advises against use during breastfeeding given the potential for serious adverse effects in the nursing infant and lack of safety data.

Folate transfers into breast milk and is important for the nursing infant's development. The recommended dietary allowance for folate during lactation is 500 mcg/day. This is independent of fezolinetant use.

Who This Combination Is Right For and Who Should Reconsider

Good Candidates for Fezolinetant Plus Folate

• Postmenopausal women with moderate-to-severe hot flashes who cannot use or prefer not to use MHT, and who take standard-dose folate (400 to 800 mcg) for general cardiovascular or bone-health support.
• Perimenopausal women with confirmed MTHFR variants who take methylfolate and are starting fezolinetant for VMS. No interaction is expected; simply continue both.
• Women with elevated homocysteine who are on folate plus B12 for vascular risk reduction. Fezolinetant does not raise homocysteine and does not interfere with the B-vitamin methylation cycle.

Women Who Should Talk to Their Prescriber First

• Women taking prescription-dose folic acid above 5 mg/day (used in some pregnancy complication protocols or hematologic conditions): inform your prescriber of both, so liver function trends can be interpreted in full context.
• Women taking methotrexate for autoimmune conditions: methotrexate is a folate antagonist, and women on methotrexate are often prescribed supplemental folate to mitigate mucositis and cytopenias. Methotrexate itself is a strong CYP substrate but does not directly affect CYP1A2 in the way that changes fezolinetant levels. Still, a woman on methotrexate is typically managed by a rheumatologist or dermatologist who should be looped in before adding fezolinetant.
• Women with CKD stage 3 or higher: renal impairment can affect folate clearance and may also modify fezolinetant pharmacokinetics. The fezolinetant label advises caution in severe renal impairment.
• Women with pre-existing liver disease: fezolinetant is contraindicated in severe hepatic impairment (Child-Pugh C). Any supplement including high-dose folate should be disclosed.

Who Should Not Use Fezolinetant Regardless of Folate Status

• Women who are pregnant or may become pregnant (see above).
• Women with severe hepatic impairment (Child-Pugh C).
• Women taking strong CYP1A2 inhibitors such as fluvoxamine or ciprofloxacin. This is the drug interaction with the highest clinical consequence; folate is not in this category.

Monitoring Plan When Taking Both

The liver monitoring schedule fezolinetant already requires creates natural check-in points for assessing your overall supplement regimen:

| Timepoint | Fezolinetant Monitoring | Folate-Related Add-On if Clinically Indicated | |---|---|---| | Baseline | LFTs (ALT, AST, bilirubin) | RBC folate, homocysteine, B12 if MTHFR positive or high CV risk | | 3 months | Repeat LFTs | Repeat homocysteine if elevated at baseline | | 6 months | Repeat LFTs; discontinue if ALT > 3x ULN | Reassess supplement list; adjust folate form if needed | | Annually | Symptom review; continue if effective | Annual labs per primary care standard |

If ALT rises above 3 times the upper limit of normal on fezolinetant, the drug should be stopped, regardless of folate use. A rise in transaminases in this context is attributed to fezolinetant until proven otherwise.

Practical Tips for Taking Both

A few straightforward points for daily use:

• No dose-separation window is required. Folate does not affect fezolinetant absorption or metabolism, so you can take them at the same time or at different times based on your routine. Fezolinetant can be taken with or without food.
• Tell every prescriber. Your gynecologist managing fezolinetant and your internist or dietitian managing your supplement regimen should both know what you are taking. This protects your liver monitoring interpretation.
• Choose the right folate form. If you have not been tested for MTHFR and you have a history of depression, recurrent pregnancy loss, or poor response to standard folic acid, ask about methylfolate (L-methylfolate, 5-MTHF) as an alternative. This is independent of Veozah but worth optimizing while you are reviewing your regimen.
• Standard supplement doses are the safe zone. The 400 to 800 mcg range used in typical adult multivitamins and B-complex supplements has no meaningful interaction signal with fezolinetant. Doses above 1 mg should be discussed with a clinician in the context of your full health picture.

A Note on the Evidence Gap

The clinical trials that supported fezolinetant's approval enrolled women for up to 52 weeks. Supplement use was recorded but interaction-specific sub-analyses for folate versus placebo have not been published as a standalone paper. The safety conclusion here rests on mechanism-based reasoning (no CYP1A2 effect, no hepatotoxic signal at standard doses, no pharmacodynamic overlap) rather than a randomized trial directly testing fezolinetant plus folate. This is standard for most supplement-drug combination assessments and is worth knowing. If your specific situation includes MTHFR variants, renal disease, or prescription-dose folate, the extrapolation is slightly thinner and direct prescriber guidance fills that gap.

Women have historically been under-enrolled in pharmacokinetic interaction studies. Drug-supplement interaction databases have even less female-specific data. The honest position: no interaction is expected, no interaction has been reported, and the mechanism does not support one. That is not the same as a head-to-head randomized trial saying so.

Reviewed by Rachel Goldberg, MD: "In my clinical practice, I routinely see perimenopausal women on fezolinetant who are also taking a B-complex or methylfolate for MTHFR support. I have not observed any interaction concern at standard supplement doses. The monitoring I watch most carefully is the liver function panel required by the fezolinetant label, and I document the full supplement list at each visit so we are interpreting those values in context."