Drug & supplement interaction

Bitter Orange + Venlafaxine

Venlafaxine brand names: Effexor XR, Effexor.

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

Venlafaxine falls into 2 drug categories that Bitter Orange can interact with; the most serious is rated moderate. Theoretically, bitter orange might have an additive effect when combined with drugs that prolong the QT interval, potentially increasing the risk of ventricular arrhythmias.

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

Bitter Orange and Venlafaxine

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

Why Are There 2 Interactions?

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

Moderate

QT INTERVAL-PROLONGING DRUGS

1 of 2

Why this applies to Venlafaxine

Venlafaxine falls under QT INTERVAL-PROLONGING DRUGS — the group Bitter Orange interacts with.

Theoretically, bitter orange might have an additive effect when combined with drugs that prolong the QT interval, potentially increasing the risk of ventricular arrhythmias.
One case report suggests that taking bitter orange in combination with other stimulants such as caffeine might prolong the QT interval in some patients.
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: venlafaxine (Effexor) can, in some people, stretch out the heart's electrical reset time, what we call the QT interval. Bitter orange supplements contain synephrine, a stimulant that may nudge your heart rate and blood pressure up and, at least in one case report, slightly affect the QT interval too. The worry is that stacking the two together could theoretically add up and raise the small risk of an irregular heartbeat.

I'll be honest with you, this is based on weak, anecdotal evidence, not strong studies, so don't panic. But because venlafaxine already comes with stimulant-like effects (faster heart rate, higher blood pressure, jitteriness), piling on another stimulant isn't ideal. Please check with your pharmacist or doctor before adding bitter orange, especially if you have any heart or blood pressure concerns.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nasir JM, Durning SJ, Ferguson M, et al. Exercise-induced syncope associated with QT prolongation and ephedra-free Xenadrine. Mayo Clin Proc 2004;79:1059-62.. PubMed
Minor

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 2

Venlafaxine also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Theoretically, bitter orange might increase levels of drug metabolized by CYP2D6.
In vitro research shows that octopamine, a constituent of bitter orange, weakly inhibits CYP2D6 enzymes. This effect has not been reported in humans.
Severity Minor 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 for venlafaxine (Effexor). Your liver uses an enzyme called CYP2D6 to help break down this medication. One compound in bitter orange (octopamine) can weakly block that enzyme in lab tests. In theory, that could let a little more venlafaxine build up in your system, which might nudge up side effects like a faster heartbeat, higher blood pressure, jitteriness, headache, or trouble sleeping.

I want to be honest about the strength of this, though. It has only been seen in a test tube, not in real people, so it's rated as a minor, theoretical concern. What worries me a bit more is the overlap: both bitter orange and venlafaxine can raise heart rate and blood pressure on their own. If you're considering this supplement, please run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. 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

Bitter Orange Also Interacts With Other Medications

Bitter Orange has 10 major, 875 moderate, 71 minor known drug interactions in our database — the Venlafaxine one above is among them. If you take anything else, check it against the full list below.

Major 10 Moderate 875 Minor 71 No known interaction 1,874 (incl. Venlafaxine)
Taking anything else?

Check Another of Your Medications Against Bitter Orange

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

From our Q&A

Questions About Bitter Orange or Venlafaxine

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

This page covers Bitter Orange only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Venlafaxine page lists 110 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 · 82 moderate · 20 minor.

From our pharmacist’s overview on the Venlafaxine page

“Venlafaxine (Effexor, Effexor XR) is an antidepressant that raises serotonin, which is exactly where part of the danger on this page sits, and its 110 interactions deserve genuine respect. Eight carry a major rating, most tied to heart rhythm: several ingredients, grapefruit among them, can stretch the QT interval and add to a strain v…”

Reviewed by 2 · Jul 18, 2026

Open the Venlafaxine interaction page

One more smart check

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

We hold 1,000 real supplement products containing Bitter Orange, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bitter Orange. Your product may carry other ingredients that interact with Venlafaxine too, on top of Bitter Orange — 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 Bitter Orange and Venlafaxine 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 Bitter Orange
Top 25%

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

29 days ago today
Medication Venlafaxine
Top 5%

#115 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 Bitter Orange

What is Bitter Orange?

Bitter Orange
  • Weight loss
  • Athletic performance and energy
  • Digestive upset
  • Appetite control
  • Aromatherapy for stress (neroli oil)

Bitter orange is a citrus fruit whose extracts contain synephrine, a mild stimulant often added to weight-loss and energy supplements. Evidence that it works for weight loss or performance is limited, and because it can raise heart rate and blood pressure, people with heart problems, high blood pressure, or who are pregnant should avoid it. Talk to your pharmacist or doctor before using it, especially if you take other stimulants.

Read the full Bitter Orange monograph & all interactions
Medication

About Venlafaxine

What Is Venlafaxine Used For?

Brand names: Effexor XR, Effexor

Venlafaxine is used to treat major depressive disorder (MDD) across all available formulations. Extended-release capsules (including Effexor XR) are also approved for generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic disorder (PD).

Extended-release tablets are approved for major depressive disorder and social anxiety disorder. Immediate-release venlafaxine tablets are indicated for major depressive disorder only.

See full Venlafaxine drug information
Keep checking

Other Drugs & Bitter Orange

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

10Major
875Moderate
71Minor
1,873No known interaction
10 Major 875 Moderate 71 Minor 1,873 No interaction
Major

10 interactions

Moderate

875 interactions

Showing 60 of 875 moderate interactions — see all 875 on the Bitter Orange page.

Minor

71 interactions

Showing 60 of 71 minor interactions — see all 71 on the Bitter Orange page.

No interaction 1,873 drugs checked — show the list

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

Showing the 60 most looked-up of 1,873 medications checked with no known interaction — see the full Bitter Orange list.

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

Can you take Bitter Orange with Venlafaxine?
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 Bitter Orange and Venlafaxine?
Venlafaxine belongs to more than one drug category, and Bitter Orange 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 Bitter Orange and Venlafaxine 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 Venlafaxine and Bitter Orange?

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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.