Drug & supplement interaction

Bitter Orange + Haloperidol

Haloperidol brand name: Haldol.

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

Haloperidol falls into 3 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
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Bitter Orange and Haloperidol

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Bitter Orange interacts with whole categories of medication. Haloperidol falls into 3 of those categories, so it can interact with Bitter Orange in 3 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 3

Why this applies to Haloperidol

Haloperidol 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 concern with pairing bitter orange and haloperidol (Haldol). Haloperidol is one of those medicines that can stretch out the heart's electrical timing, what we call the QT interval. Bitter orange contains synephrine, a mild stimulant that can nudge up your heart rate and blood pressure, and there's a thought that it might add a little to that same QT effect, especially if you're also getting caffeine or other stimulants.

I want to be honest about how soft this evidence is. It's really just theory plus a single case report, not strong proof. For most people the risk is low, but a prolonged QT can rarely lead to dangerous heart rhythms, so it's worth a quick chat with your pharmacist or doctor before combining them, particularly if you have a heart condition.

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
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 3

Haloperidol also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Bitter orange might increase levels of drugs metabolized by CYP3A4.
Small clinical studies suggest that single or multiple doses of freshly squeezed bitter orange juice 200-240 mL can inhibit CYP3A4 metabolism of drugs, causing increased drug levels and potentially increasing the risk of adverse effects. However, the extent of the effect of bitter orange on CYP3A4-mediated drug interactions is unknown. Some evidence suggests that bitter orange selectively inhibits intestinal CYP3A4, but not hepatic CYP3A4. Its effect on P-glycoprotein, which strongly overlaps with CYP3A4 interactions, is unclear. One small clinical study shows that drinking 8 ounces of freshly squeezed bitter orange juice has no effect on cyclosporine, which seems to be more dependent on hepatic CYP3A4 and P-glycoprotein than intestinal CYP3A4.
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 Haloperidol (Haldol): your body partly relies on an enzyme called CYP3A4 to break this medicine down. Bitter orange can slow that enzyme down, mostly in the gut. When the enzyme is blocked, a bit more haloperidol may stay in your system than usual, which could nudge up its effects and side effects, things like drowsiness, dizziness, muscle stiffness, restlessness, or in rare cases changes to your heart rhythm.

That said, the evidence here is fairly limited and comes from small studies, so the real-world impact isn't fully known. Everyday culinary amounts are unlikely to be a big deal, but concentrated weight-loss or energy supplements are a different story. Please check with your pharmacist or doctor before pairing the two, and don't change your haloperidol on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Malhotra S, Bailey DG, Paine MF, Watkins PB. Seville orange juice-felodipine interaction: comparison with dilute grapefruit juice and involvement of furocoumarins. Clin Pharmacol Ther 2001;69:14-23. PubMed
  2. Penzak SR, Acosta EP, Turner M, et al. Effect of Seville orange juice and grapefruit juice on indinavir pharmacokinetics. J Clin Pharmacol 2002;42:1165-70. PubMed
  3. Edwards DJ, Fitzsimmons ME, Schuetz EG, et al. 6',7'-Dihydroxybergamottin in grapefruit juice and Seville orange juice: effects on cyclosporine disposition, enterocyte CYP3A4, and P-glycoprotein. Clin Pharmacol Ther 1999;65:237-44. PubMed
  4. Di Marco MP, Edwards DJ, Wainer IW, Ducharme MP. The effect of grapefruit juice and seville orange juice on the pharmacokinetics of dextromethorphan: the role of gut CYP3A and P-glycoprotein. Life Sci 2002;71:1149-60. PubMed
  5. Abdelkawy KS, Donia AM, Turner RB, Elbarbry F. Effects of Lemon and Seville Orange Juices on the Pharmacokinetic Properties of Sildenafil in Healthy Subjects. Drugs R D. 2016 Sep;16(3):271-278. PubMed
Minor

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

3 of 3

Haloperidol 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 Haldol: your body partly relies on a liver enzyme called CYP2D6 to clear it out. In lab dish studies, a compound in bitter orange (octopamine) weakly slowed that same enzyme down. If that happened in people, haloperidol could clear a little slower and build up, which in theory might mean more of its usual side effects like drowsiness, dizziness, muscle stiffness, restlessness, or those involuntary movements.

The honest truth, though, is that this has only been seen in test tubes, never in actual people, and the interaction is rated minor. There's a separate point worth a mention: bitter orange is a stimulant that can nudge up heart rate and blood pressure, so combining it with any medication takes a quick chat with 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 Haloperidol 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. Haloperidol)
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.

Everything else you take

See Every Supplement That Interacts With Haloperidol

This page covers Bitter Orange only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Haloperidol page lists 211 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: 11 major · 157 moderate · 43 minor.

From our pharmacist’s overview on the Haloperidol page

“Haloperidol (Haldol) is a potent antipsychotic prescribed for schizophrenia and severe agitation, and the 211 supplements on this list warrant genuine care, starting with the 11 rated major. Most of the trouble runs through the liver enzymes that clear haloperidol from the body.”

Reviewed by 2 · Jul 18, 2026

Open the Haloperidol 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 Haloperidol 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 Haloperidol 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 Haloperidol
Top half

#1,227 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 Haloperidol

What Is Haloperidol Used For?

Brand name: Haldol

Haloperidol is used to manage symptoms of psychotic disorders and to control the tics and vocal outbursts of Tourette's disorder in both children and adults.

In children, it is also used for severe combative or explosive behavior problems, and for hyperactivity with conduct disorders — but only when other treatments like therapy or non-antipsychotic medications have not worked.

See full Haloperidol 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 Haloperidol, 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 Haloperidol supplement interactions › Every supplement checked against Haloperidol, ranked by severity Haloperidol 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 Haloperidol Together: Common Questions

Can you take Bitter Orange with Haloperidol?
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 3 interactions listed for Bitter Orange and Haloperidol?
Haloperidol 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 Haloperidol 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 Haloperidol 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.