Drug & supplement interaction

Ergot + Fluoxetine

Fluoxetine brand names: Prozac, Sarafem.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Fluoxetine falls into 2 drug categories that Ergot can interact with; the most serious is rated moderate. Certain ergot alkaloids, such as dihydroergotamine, act as serotonin agonists.

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

Ergot and Fluoxetine

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

Why Are There 2 Interactions?

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

Moderate

SEROTONERGIC DRUGS

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Why this applies to Fluoxetine

Fluoxetine falls under SEROTONERGIC DRUGS — the group Ergot interacts with.

Certain ergot alkaloids, such as dihydroergotamine, act as serotonin agonists. Theoretically, combining serotonergic drugs with ergot might increase the risk of serotonergic side effects including serotonin syndrome and cerebral vasoconstrictive disorders. Monitor patients for signs of serotonin syndrome and other serotonergic side effects if using ergot with serotonergic drugs.
Serotonergic drugs include the selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft); tricyclic and atypical antidepressants such as amitriptyline (Elavil), clomipramine (Anafranil), and imipramine (Tofranil); triptans such as sumatriptan (Imitrex), zolmitriptan (Zomig), and rizatriptan (Maxalt); opioids such as methadone (Dolophine) and tramadol (Ultram); and many other medications.
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: fluoxetine (Prozac) raises serotonin levels in your brain, and certain ergot chemicals also nudge serotonin pathways. Stack them together and, in theory, you could push serotonin too high. That can lead to serotonin syndrome, with symptoms like agitation, a racing heart, sweating, shaking, muscle twitching, or confusion. Both can also tighten blood vessels, which is another reason caution makes sense.

I'll be honest with you, this concern is based on weak, anecdotal evidence, not strong studies, so it's a maybe rather than a sure thing. Still, raw ergot is genuinely toxic and isn't safe to take on its own. Please don't change your Prozac, but do check with your pharmacist or doctor before using anything containing ergot.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  2. Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

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Fluoxetine also falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS.

Ergotamine, a constituent of ergot, is a substrate of cytochrome P450 3A4 (CYP3A4). Theoretically, drugs that inhibit CYP3A4 might increase the risk of ergot toxicity. Some of these drugs include amiodarone (Cordarone), clarithromycin (Biaxin), diltiazem (Cardizem), erythromycin (E-mycin, Erythrocin), indinavir (Crixivan), ritonavir (Norvir), saquinavir (Fortovase, Invirase), and many others.
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: ergot's main active chemical, ergotamine, gets cleared from your body by a liver enzyme called CYP3A4. Fluoxetine (Prozac) is a known blocker of that enzyme, so if the two are taken together, your body may break down ergot more slowly. That can let ergot build up and raise the chance of ergot toxicity, which can show up as cold or tingly hands and feet, leg cramps, headache, nausea, or in serious cases, dangerously narrowed blood vessels.

I'll be honest, this one rests on weak, anecdotal evidence and is largely theoretical. But ergot is genuinely toxic and tough to dose safely, so I wouldn't combine them on your own. Please run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34. 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

Ergot Also Interacts With Other Medications

Ergot has 461 moderate known drug interactions in our database — the Fluoxetine one above is among them. If you take anything else, check it against the full list below.

Moderate 461 No known interaction 2,369 (incl. Fluoxetine)
Taking anything else?

Check Another of Your Medications Against Ergot

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

From our Q&A

Questions About Ergot or Fluoxetine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Ergot or Fluoxetine, 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 Fluoxetine

This page covers Ergot only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluoxetine page lists 163 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 8 major · 127 moderate · 28 minor.

From our pharmacist’s overview on the Fluoxetine page

“Grapefruit is the surprise at the top of fluoxetine's (Prozac) supplement list. In large amounts it can stretch the QT interval, the electrical pause between heartbeats, and fluoxetine, a widely prescribed antidepressant, can do the same, raising the odds of a dangerous rhythm.”

Reviewed by 2 · Jul 18, 2026

Open the Fluoxetine interaction page

How much people look this up

Where Ergot and Fluoxetine 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 Ergot
Top half

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

29 days ago today
Medication Fluoxetine
Top 5%

#45 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 Ergot

What is Ergot?

Ergot
  • Heavy menstrual or uterine bleeding
  • Bleeding after childbirth
  • Migraine headaches
  • Stimulating uterine contractions

Ergot is a toxic fungus that grows on rye and contains powerful chemicals (ergot alkaloids) that strongly narrow blood vessels and squeeze the uterus. Because raw ergot is poisonous and the dose is impossible to control safely, it should never be used as a home remedy or supplement. Some purified ergot chemicals are used as prescription drugs under strict medical supervision, but the crude herb is not safe to take.

Read the full Ergot monograph & all interactions
Medication

About Fluoxetine

What Is Fluoxetine Used For?

Brand names: Prozac, Sarafem

Fluoxetine is approved to treat four conditions: major depressive disorder (MDD), obsessive-compulsive disorder (OCD), bulimia nervosa (a binge-eating and purging disorder), and panic disorder — with or without agoraphobia (fear of situations that feel hard to escape).

It works for adults across all four conditions, and for children and teens with depression (ages 8–18) and OCD (ages 7–17).

See full Fluoxetine drug information
Keep checking

Other Drugs & Ergot

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

0Major
461Moderate
0Minor
2,368No known interaction
461 Moderate 2,368 No interaction
Moderate

461 interactions

Showing 60 of 461 moderate interactions — see all 461 on the Ergot page.

No interaction 2,368 drugs checked — show the list

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

Showing the 60 most looked-up of 2,368 medications checked with no known interaction — see the full Ergot list.

See the full Ergot interactions page
See every supplement checked against Fluoxetine, ranked by severity
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

Keep exploring
Ergot monograph › Uses, safety, and every drug interaction in one place Fluoxetine supplement interactions › Every supplement checked against Fluoxetine, ranked by severity Fluoxetine drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Ergot and Fluoxetine Together: Common Questions

Can you take Ergot with Fluoxetine?
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 Ergot and Fluoxetine?
Fluoxetine belongs to more than one drug category, and Ergot 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 Ergot and Fluoxetine 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 Fluoxetine and Ergot?

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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.