Drug & supplement interaction

Hops + Haloperidol

Haloperidol brand name: Haldol.

Minor Interaction
Medically reviewed by · Updated October 2026
The bottom line Minor

Haloperidol falls into 2 drug categories that Hops can interact with; the most serious is rated minor. Hops extract does not seem to affect the metabolism of CYP1A2 substrates.

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

Hops and Haloperidol

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

Why Are There 2 Interactions?

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

Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 2

Why this applies to Haloperidol

Haloperidol falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Hops interacts with.

Hops extract does not seem to affect the metabolism of CYP1A2 substrates.
In vitro research suggests that flavonoid constituents of hops inhibit CYP1A2 enzyme activity. However, a pharmacokinetic study in healthy postmenopausal patients shows that taking a standardized extract of spent hops containing prenylated phenols, as 59.5 mg twice daily for 2 weeks, does not affect levels of caffeine, a CYP1A2 probe substrate.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the short version: this one really isn't something to lose sleep over. Your body uses a liver enzyme called CYP1A2 to help clear haloperidol (Haldol). In a test tube, certain flavonoids in hops looked like they might slow that enzyme down, which in theory could let haloperidol build up a bit and cause more drowsiness, stiffness, or restlessness. But theory and real life don't always match.

When researchers actually gave people a standardized hops extract for two weeks, it did not change how the body handled a CYP1A2 test drug. So in practice, hops is very unlikely to meaningfully affect your haloperidol. Since both can make you sleepy, just mention any new supplement to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Henderson MC, Miranda CL, Stevens JF, et al. In vitro inhibition of human P450 enzymes by prenylated flavonoids from hops, Humulus lupulus. Xenobiotica 2000;30:235-51.. PubMed
  2. van Breemen RB, Chen L, Tonsing-Carter A, et al. Pharmacokinetic Interactions of a Hop Dietary Supplement with Drug Metabolism in Perimenopausal and Postmenopausal Women. J Agric Food Chem. 2020;68(18):5212-5220. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

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

Theoretically, hops extract might alter metabolism of CYP3A4 substrates; however, this effect may not be clinically significant.
Animal research suggests that specific constituents of hops, called lupulones, can induce hepatic CYP3A4 enzyme activity. However, a pharmacokinetic study in healthy postmenopausal patients with normal metabolism shows that taking a standardized extract of spent hops containing prenylated phenols, as 59.5 mg twice daily for 2 weeks, decreases the concentration of alprazolam, a CYP3A4 probe substrate, by 7.6%. This reduction is unlikely to be clinically relevant.
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 (haloperidol) and hops. Your liver uses an enzyme called CYP3A4 to help break this medication down, and some lab and animal studies hint that compounds in hops (lupulones) might speed that enzyme up a little. If that happened in real life, it could in theory clear haloperidol a touch faster and make it slightly less effective at calming psychotic symptoms or tics.

The honest truth, though, is that the human evidence is very weak. A study using a similar CYP3A4 test drug found only about an 8% change, which is too small to matter for most people. So this is mostly theoretical. Since haloperidol is a serious medication, just give your pharmacist or doctor a quick heads-up before adding a hops supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mannering, G. J., Shoeman, J. A., and Deloria, L. B. Identification of the antibiotic hops component, colupulone, as an inducer of hepatic cytochrome P-4503A in the mouse. Drug Metab Dispos 1992;20(2):142-147. DOI
  2. van Breemen RB, Chen L, Tonsing-Carter A, et al. Pharmacokinetic Interactions of a Hop Dietary Supplement with Drug Metabolism in Perimenopausal and Postmenopausal Women. J Agric Food Chem. 2020;68(18):5212-5220. 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

Hops Also Interacts With Other Medications

Hops has 289 moderate, 575 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.

Moderate 289 Minor 575 No known interaction 1,966 (incl. Haloperidol)
Taking anything else?

Check Another of Your Medications Against Hops

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

Everything else you take

See Every Supplement That Interacts With Haloperidol

This page covers Hops 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 Hops as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,325 real supplement products containing Hops, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hops. Your product may carry other ingredients that interact with Haloperidol too, on top of Hops — 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 Hops 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 Hops
Top 25%

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

29 days ago today
Medication Haloperidol
Steady interest

#2,025 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 Hops

What is Hops?

Hops
  • Sleep problems and insomnia
  • Anxiety and restlessness
  • Menopausal symptoms
  • Mild digestive complaints
  • Flavoring in beer and food

Hops are most often used for sleep and mild anxiety, frequently combined with valerian, but the human evidence is limited and not very strong. They are generally well tolerated when used short-term, though they may cause drowsiness, and should be avoided during pregnancy and breastfeeding because their safety is unknown.

Read the full Hops monograph & all interactions
Medication

About Haloperidol

What Is Haloperidol Used For?

Brand name: Haldol

Haloperidol treats schizophrenia and other psychotic disorders. Uses depend on the product.

Haloperidol tablets and oral solution are also used to control tics and vocal utterances of Tourette’s Disorder in children and adults. They are used for severe behavior problems and hyperactivity in children, but only after psychotherapy or non-antipsychotic medicines have failed. One haloperidol injection product (Haloperidol, intramuscular) is also labeled for Tourette’s Disorder. Haloperidol decanoate injections (including Haldol Decanoate) are for schizophrenia only.

See full Haloperidol drug information Haloperidol NDC codes and packages
Keep checking

Other Drugs & Hops

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

0Major
289Moderate
575Minor
1,965No known interaction
289 Moderate 575 Minor 1,965 No interaction
Moderate

289 interactions

Showing 60 of 289 moderate interactions — see all 289 on the Hops page.

Minor

575 interactions

Showing 60 of 575 minor interactions — see all 575 on the Hops page.

No interaction 1,965 drugs checked — show the list

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

Showing the 60 most looked-up of 1,965 medications checked with no known interaction — see the full Hops list.

See the full Hops 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
Hops 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 Haloperidol NDC codes and packages › Every package, labeler and price in the FDA directory 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 Hops and Haloperidol Together: Common Questions

Can you take Hops with Haloperidol?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Hops and Haloperidol?
Haloperidol belongs to more than one drug category, and Hops 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 Hops and Haloperidol interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Haloperidol and Hops?

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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.