Drug & supplement interaction

Grapefruit + Clomipramine

Clomipramine brand names: Anafranil, Anafranil SR.

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

Clomipramine falls into 5 drug categories that Grapefruit can interact with; the most serious is rated major. Grapefruit juice can increase levels of drugs metabolized by CYP3A4.

Read the full interaction report
SeverityMajor
LikelihoodLikely
Interactions5
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Grapefruit and Clomipramine

These two interact in 5 distinct ways. Each one is explained separately below.

Why Are There 5 Interactions?

Grapefruit interacts with whole categories of medication. Clomipramine falls into 5 of those categories, so it can interact with Grapefruit in 5 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Major).

Major

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 5

Why this applies to Clomipramine

Clomipramine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Grapefruit interacts with.

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.
Clinical research shows that grapefruit juice can inhibit CYP3A4 metabolism of drugs, causing increased drug levels and potentially increasing the risk of adverse effects. When taken orally, effects of grapefruit juice on CYP3A4 levels appear to last at least 48 hours. Grapefruit's ability to inhibit CYP3A4 has even been harnessed to intentionally increase levels of venetoclax, which is metabolized by CYP3A4, in an elderly patient with acute myeloid leukemia who could not afford full dose venetoclax. The lower dose of venetoclax in combination with grapefruit juice resulted in serum levels of venetoclax in the therapeutic reference range of full dose venetoclax and positive treatment outcomes for the patient.
Professional consensus recommends the consideration of patient age, existing medical conditions, additional medications, and the potential for additive adverse effects when evaluating the risks of concomitant use of grapefruit juice with any medication metabolized by CYP3A4. While all patients are at risk for interactions with grapefruit juice consumption, patients older than 70 years of age and those taking multiple medications are at the greatest risk for a serious or fatal interaction with grapefruit juice.
Severity Major Likelihood Likely Evidence B

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Here's the short version: your body uses a liver enzyme called CYP3A4 to help clear clomipramine out of your system. Grapefruit slows that enzyme down, and that effect can linger for up to two days after you eat or drink it. Since clomipramine is an active drug (not a prodrug that needs switching on), blocking this pathway tends to let it build up in your blood.

More clomipramine on board can mean stronger side effects, such as a dry mouth, constipation, blurry vision, drowsiness, dizziness on standing, or a faster or irregular heartbeat. That heart effect is the one I worry about most, especially if you're older or take other medicines. An occasional bite of grapefruit usually isn't a big deal, but regular juice or whole fruit is worth a quick chat with your pharmacist or doctor before you make it a habit.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lilja JJ, Kivisto KT, Neuvonen PJ. Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin. Clin Pharmacol Ther 1999;66:118-27. DOI
  2. Lilja JJ, Kivisto KT, Neuvonen PJ. Grapefruit juice-simvastatin interaction: effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors. Clin Pharmacol Ther 1998;64:477-83. PubMed
  3. Jetter A, Kinzig-Schippers M, Walchner-Bonjean M, et al. Effects of grapefruit juice on the pharmacokinetics of sildenafil. Clin Pharmacol Ther 2002;71:21-9. PubMed
  4. Fuhr U, Muller-Peltzer H, Kern R, et al. Effects of grapefruit juice and smoking on verapamil concentrations in steady state. Eur J Clin Pharmacol 2002;58:45-53. PubMed
  5. Kanazawa S, Ohkubo T, Sugawara K. The effects of grapefruit juice on the pharmacokinetics of erythromycin. Eur J Clin Pharmacol 2001;56:799-803. PubMed
  6. Charbit, B., Becquemont, L., Lepere, B., Peytavin, G., and Funck-Brentano, C. Pharmacokinetic and pharmacodynamic interaction between grapefruit juice and halofantrine. Clin Pharmacol Ther 2002;72(5):514-523. PubMed
  7. Tanaka S, Uchida S, Miyakawa S, Inui N, Takeuchi K, Watanabe H, Namiki N. Comparison of inhibitory duration of grapefruit juice on organic anion-transporting polypeptide and cytochrome P450 3A4. Biol Pharm Bull. 2013;36(12):1936-41. PubMed
  8. Bailey DG. Predicting clinical relevance of grapefruit-drug interactions: a complicated process. J Clin Pharm Ther. 2017 Apr;42(2):125-27. PubMed
  9. Mouly S, Lloret-Linares C, Sellire PO, Sene D, Bergmann JF. Is the clinical relevance of drug-food and drug-herb interactions limited to grapefruit juice and Saint-John's Wort? Pharmacol Res. 2017 Apr;118:82-92. PubMed
  10. Loretz C, Ho MD, Alam N, Mitchell W, Li AP. Application of cryopreserved human intestinal mucosa and cryopreserved human enterocytes in the evaluation of herb-drug interactions: evaluation of CYP3A inhibitory potential of grapefruit juice and commercial f
  11. Long Z, Ruan M, Wu W, Zeng Q, Li Q, Huang Z. The successful combination of grapefruit juice and venetoclax in an unfit acute myeloid leukemia patient with adverse risk: A case report. Front Oncol 2022;12:912696. PubMed
Major

CLOMIPRAMINE (Anafranil)

2 of 5
Theoretically, grapefruit juice might increase blood levels of clomipramine, potentially increasing the effects and adverse effects of clomipramine.
Case reports have shown that clomipramine trough levels increase significantly after the addition of grapefruit juice to the therapeutic regimen.
Severity Major Likelihood Probable Evidence D

Interaction 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..

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

Here's the deal with grapefruit and clomipramine. Your body uses certain liver enzymes to clear this medicine out, and grapefruit can slow those enzymes down. Clomipramine works as-is (it isn't a prodrug that needs activating), so when it isn't cleared as quickly, the level in your blood can creep up. A few real case reports actually showed clomipramine levels rising after grapefruit was added in.

What might that feel like? More of the usual clomipramine side effects, things like drowsiness, dry mouth, constipation, blurry vision, dizziness, or a faster heartbeat. The evidence here is mostly anecdotal, but because the effect points one clear direction, it's worth a quick chat with your pharmacist or doctor before you make grapefruit a regular habit. Please don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Oesterheld J, Kallepalli BR. Grapefruit juice and clomipramine: shifting metabolitic ratios. J Clin Psychopharmacol 1997;17:62-3. PubMed
Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

3 of 5

Clomipramine also falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES.

Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP2C19.
In vitro research suggests that grapefruit juice might inhibit CYP2C19 enzymes. Also, a small clinical study shows that taking grapefruit juice with clopidogrel, an antiplatelet prodrug that is metabolized primarily by CYP2C19, decreases plasma levels of the active metabolite and impairs the antiplatelet effect of clopidogrel. This effect is likely due to grapefruit-induced inhibition of CYP2C19.
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 with grapefruit and clomipramine. Your body uses an enzyme called CYP2C19 to help break this medicine down. Grapefruit appears to slow that enzyme, so the clomipramine in your system may clear out a little more slowly and build up over time. Unlike clopidogrel (a prodrug that grapefruit weakens), clomipramine is the active drug itself, so blocking its breakdown tends to increase its effect.

In real life that could mean more of clomipramine's usual side effects, like a dry mouth, drowsiness, constipation, dizziness, or a faster heartbeat. The evidence here is fairly theoretical and on the weaker side, so I wouldn't panic. Still, please check with your pharmacist or doctor before making grapefruit a regular habit.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Holmberg MT, Tornio A, Neuvonen M, Neuvonen PJ, Backman JT, Niemi M. Grapefruit juice inhibits the metabolic activation of clopidogrel. Clin Pharmacol Ther. 2014 Mar;95(3):307-13. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

4 of 5

Clomipramine also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP1A2.
In vitro research suggests that grapefruit juice might inhibit CYP1A2 enzymes. So far, this interaction has not been reported in humans.
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 with clomipramine and grapefruit. Your body uses an enzyme called CYP1A2 (along with others) to break clomipramine down. Some lab studies hint that compounds in grapefruit might slow that enzyme a bit. If that happened, clomipramine could clear more slowly and build up in your system, which in theory could mean stronger effects and more side effects like drowsiness, dry mouth, constipation, blurry vision, or a faster heartbeat.

The honest part: this comes from test-tube research only, and it hasn't actually been seen in real people. So I wouldn't lose sleep over it, but since clomipramine is a serious medicine, it's worth a quick chat with your pharmacist or doctor before adding regular grapefruit.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

5 of 5

Clomipramine also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP2C9.
In vitro research suggests that grapefruit juice might inhibit CYP2C9 enzymes. So far, this interaction has not been reported in humans.
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 with grapefruit and clomipramine. Grapefruit can block a liver enzyme (CYP2C9) that helps your body clear this medicine. If that pathway slows down, clomipramine could build up a bit more than expected, which in theory might mean stronger effects like drowsiness, dry mouth, constipation, blurred vision, dizziness, or a faster heartbeat. Clomipramine is the active drug itself, not a prodrug, so more of it in your system means more effect, not less.

That said, this concern comes only from lab (test-tube) studies and has not been seen in real people yet, so I wouldn't panic. An occasional grapefruit is unlikely to be a big deal, but check with your pharmacist or doctor before making it a daily habit.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 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

Grapefruit Also Interacts With Other Medications

Grapefruit has 775 major, 151 moderate, 63 minor known drug interactions in our database — the Clomipramine one above is among them. If you take anything else, check it against the full list below.

Major 775 Moderate 151 Minor 63 No known interaction 1,841 (incl. Clomipramine)
Taking anything else?

Check Another of Your Medications Against Grapefruit

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

From our Q&A

Questions About Grapefruit or Clomipramine

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

This page covers Grapefruit only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clomipramine page lists 236 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 5 major · 179 moderate · 52 minor.

From our pharmacist’s overview on the Clomipramine page

“A tricyclic antidepressant used mostly for OCD, clomipramine (Anafranil) is unforgiving of shifts in its blood level, which is why its 236 supplement interactions deserve genuine wariness. Most of the list involves metabolism: herbs that speed up or slow down the liver enzymes handling clomipramine can drag its level too low or push it…”

Reviewed by 2 · Jul 18, 2026

Open the Clomipramine interaction page

One more smart check

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

We hold 1,144 real supplement products containing Grapefruit, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Grapefruit. Your product may carry other ingredients that interact with Clomipramine too, on top of Grapefruit — 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 Grapefruit and Clomipramine 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 Grapefruit
Top 10%

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

29 days ago today
Medication Clomipramine
Steady interest

#1,910 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 Grapefruit

What is Grapefruit?

Grapefruit
  • Source of vitamin C
  • Digestive complaints
  • Antimicrobial (seed extract)
  • Weight management
  • Skin and cosmetic uses

Grapefruit is a nutritious citrus fruit rich in vitamin C and other nutrients, and it is generally safe to eat. However, grapefruit is famous for serious interactions with many prescription medicines, so anyone taking medication should check with a pharmacist or doctor before consuming it regularly.

Read the full Grapefruit monograph & all interactions
Medication

About Clomipramine

What Is Clomipramine Used For?

Brand names: Anafranil, Anafranil SR

Clomipramine — sold as Anafranil and under the generic name Clomipramine Hydrochloride — is approved to treat obsessions and compulsions in people with Obsessive-Compulsive Disorder (OCD). This includes adults and children/adolescents ages 10 to 17.

To qualify for treatment, the obsessions or compulsions must cause significant distress, take up a lot of time, or noticeably interfere with work, school, or social life.

See full Clomipramine drug information
Keep checking

Other Drugs & Grapefruit

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

775Major
151Moderate
63Minor
1,840No known interaction
775 Major 151 Moderate 63 Minor 1,840 No interaction
Major

775 interactions

Showing 60 of 775 major interactions — see all 775 on the Grapefruit page.

Moderate

151 interactions

Showing 60 of 151 moderate interactions — see all 151 on the Grapefruit page.

Minor

63 interactions

Showing 60 of 63 minor interactions — see all 63 on the Grapefruit page.

No interaction 1,840 drugs checked — show the list

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

Showing the 60 most looked-up of 1,840 medications checked with no known interaction — see the full Grapefruit list.

See the full Grapefruit interactions page
See every supplement checked against Clomipramine, 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
Grapefruit monograph › Uses, safety, and every drug interaction in one place Clomipramine supplement interactions › Every supplement checked against Clomipramine, ranked by severity Clomipramine 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 Grapefruit and Clomipramine Together: Common Questions

Can you take Grapefruit with Clomipramine?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 5 interactions listed for Grapefruit and Clomipramine?
Clomipramine belongs to more than one drug category, and Grapefruit 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 Grapefruit and Clomipramine interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Clomipramine and Grapefruit?

Our pharmacists answer your medication & supplement questions — free.

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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.