Drug & supplement interaction

Black Cohosh + Fluvoxamine

Fluvoxamine brand name: Luvox.

Moderate Interaction
The bottom line Moderate

Fluvoxamine falls into 2 drug categories that Black Cohosh can interact with; the most serious is rated moderate. Some research suggests that black cohosh might inhibit CYP2D6, but there is conflicting evidence.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Black Cohosh and Fluvoxamine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Black Cohosh interacts with whole categories of medication. Fluvoxamine falls into 2 of those categories, so it can interact with Black Cohosh in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 2

Why this applies to Fluvoxamine

Fluvoxamine falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Black Cohosh interacts with.

Some research suggests that black cohosh might inhibit CYP2D6, but there is conflicting evidence.
Some clinical research suggests that black cohosh might modestly inhibit CYP2D6 and increase levels of drugs metabolized by this enzyme. However, contradictory clinical research shows a specific black cohosh product (Remifemin, Enzymatic Therapy) 40 mg twice daily does not significantly inhibit metabolism of a CYP2D6 substrate in healthy study volunteers. Until more is known, use black cohosh cautiously in patients taking drugs metabolized by CYP2D6.
Severity Moderate Likelihood Possible Evidence B

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for these two together. Your body partly relies on a liver enzyme called CYP2D6 to help break down fluvoxamine. Some studies hint that black cohosh might mildly slow that enzyme down. If it does, a bit more fluvoxamine could linger in your system, which in theory could nudge up side effects like nausea, drowsiness, headache, trouble sleeping, or jitteriness.

I want to keep this in perspective, though. The evidence is genuinely mixed, and one good study of a common black cohosh product found no meaningful effect. So this is a possible, modest interaction, not a sure thing. Short-term, occasional use likely matters less than steady daily dosing. Still, since you're on fluvoxamine, it's worth a quick chat with your pharmacist or doctor before starting black cohosh.

References
  1. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
  2. Gurley BJ, Swain A, Hubbard MA, et al. Clinical assessement of CYP2D6-mediated herb-drug interactions in humans: Effects of milk-thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea. Mol Nutr Food Res 2008;52:755-63.
Moderate

SEROTONERGIC DRUGS

2 of 2

Fluvoxamine also falls under SEROTONERGIC DRUGS.

Combining serotonergic drugs with black cohosh might cause additive serotonergic effects.
Black cohosh might increase the risk of serotonin syndrome when combined with other serotonergic drugs. Black cohosh acts as an agonist at several serotonin receptor subtypes and might interact with other serotonergic medications. In one case, a 55-year-old female who had been on stable treatment with sertraline 50 mg and duloxetine 60 mg daily developed serotonin syndrome after taking black cohosh extract 40 mg daily for 3 days.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist: fluvoxamine (Luvox) is an SSRI that already raises serotonin levels in your brain. Black cohosh seems to nudge certain serotonin receptors too, so stacking the two could, in theory, push serotonin activity higher than you want. When that happens, you might notice signs of serotonin syndrome, like agitation, a racing heart, sweating, shivering, muscle twitching, or feeling unusually restless or confused.

I want to be honest about the evidence, though. This concern comes mostly from lab work, plus one case report involving different antidepressants, so it's not a strong or proven interaction. Most people taking black cohosh briefly do fine. Still, since you're on fluvoxamine, it's worth a quick chat with your pharmacist or doctor before adding it, and watch for those symptoms if you do start it.

References
  1. Dernbach MR, Carpenter JE, Shah N, Carter GB. Black Cohosh Interactions with Prescription Medications Associated with Serotonin Toxicity and Rhabdomyolysis: A Case Report. J Emerg Med 2024;66(5):e592-e596. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Black Cohosh Also Interacts With Other Medications

Black Cohosh has 637 moderate, 16 minor known drug interactions in our database — the Fluvoxamine one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Black Cohosh

Covers the 2,830 medications we’ve checked against Black Cohosh. Pick one to open its full report.

From our Q&A

Questions About Black Cohosh or Fluvoxamine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Black Cohosh or Fluvoxamine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Fluvoxamine

This page covers Black Cohosh only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluvoxamine page lists 193 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 1,3-dmaa (moderate), 5-htp (moderate) and Acacia Rigidula (moderate).

By severity: 2 major · 151 moderate · 40 minor.

From our pharmacist’s overview on the Fluvoxamine page

“Fluvoxamine (Luvox), an SSRI used for OCD and depression, carries an interaction list that deserves genuinely careful reading. Two entries matter most: lithium, which alongside a serotonin-raising drug like fluvoxamine can tip toward serotonin syndrome, a dangerous excess of serotonin, and activated charcoal, which can soak up the medi…”

Reviewed by 2 · Jul 18, 2026

Open the Fluvoxamine interaction page

One more smart check

Taking Black Cohosh as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,472 real supplement products containing Black Cohosh, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Black Cohosh. Your product may carry other ingredients that interact with Fluvoxamine too, on top of Black Cohosh — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Black Cohosh and Fluvoxamine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Black Cohosh
Top 25%

#157 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Fluvoxamine
Steady interest

#1,777 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Black Cohosh

What is Black Cohosh?

Black Cohosh
  • Hot flashes and night sweats
  • Other menopause symptoms
  • Mood changes during menopause
  • Premenstrual syndrome (PMS)
  • Menstrual cramps

Black cohosh is a North American plant most often used to ease menopause symptoms like hot flashes, but the research is mixed and far from settled. It is generally well tolerated for short-term use, though rare reports of liver problems mean you should talk with your pharmacist or doctor before trying it, especially if you have liver disease.

Read the full Black Cohosh monograph & all interactions
Medication

About Fluvoxamine

What Is Fluvoxamine Used For?

Brand name: Luvox

Fluvoxamine is used to treat obsessive compulsive disorder (OCD). OCD involves unwanted, repeated thoughts or images (obsessions) and repeated behaviors (compulsions) that cause distress or get in the way of daily life.

Fluvoxamine maleate tablets treat obsessions and compulsions in people with OCD, including children and adolescents ages 8 to 17. Fluvoxamine maleate extended-release capsules are also indicated for OCD; the capsule's own trial was in adults.

See full Fluvoxamine drug information
Keep checking

Other Drugs & Black Cohosh

Browse every other medication we’ve checked against Black Cohosh — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
637Moderate
16Minor
2,176No known interaction
Moderate

637 interactions

Showing 60 of 637 moderate interactions — see all 637 on the Black Cohosh page.

Minor

16 interactions

No interaction 2,176 drugs checked — show the list

We also checked Black Cohosh against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,176 medications checked with no known interaction — see the full Black Cohosh list.

Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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Pharmacist Counseling Corner

Taking Black Cohosh and Fluvoxamine Together: Common Questions

Can you take Black Cohosh with Fluvoxamine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Black Cohosh and Fluvoxamine?
Fluvoxamine belongs to more than one drug category, and Black Cohosh interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Black Cohosh and Fluvoxamine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Fluvoxamine and Black Cohosh?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.