Drug & supplement interaction

Hops + Chlorpheniramine

Chlorpheniramine brand names: Chlor-Trimeton, Teldrin.

Minor Interaction
The bottom line Minor

Hops has a minor interaction with Chlorpheniramine. Theoretically, hops extract might alter metabolism of CYP3A4 substrates; however, this effect may not be clinically significant.

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

Hops and Chlorpheniramine

Here is the interaction we found between these two, with the evidence behind it.

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Chlorpheniramine

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

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 short version: this one is mostly theoretical, so I wouldn't lose sleep over it. The thinking is that hops might gently nudge a liver enzyme called CYP3A4, which helps break down chlorpheniramine. If hops sped that enzyme up, your body could clear the antihistamine a touch faster, which in theory means slightly less allergy relief (a little more sneezing or runny nose).

But the real-world numbers are tiny. In a human study, a hops extract changed levels of a similar drug by under 8 percent, which is too small to matter. One thing worth flagging: both hops and chlorpheniramine can make you drowsy, so together you may feel more sleepy. If you're using both regularly, just mention it to your pharmacist.

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, 573 minor known drug interactions in our database — the Chlorpheniramine one above is one of them. If you take anything else, check it against the full list below.

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.

From our Q&A

Questions About Hops or Chlorpheniramine

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

This page covers Hops only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorpheniramine page lists 198 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Henbane (major), Lithium (major) and Scopolia (major).

By severity: 6 major · 149 moderate · 43 minor.

From our pharmacist’s overview on the Chlorpheniramine page

“An over-the-counter allergy pill sounds harmless, but chlorpheniramine (Chlor-Trimeton) has one of the longer supplement interaction lists I review, and it calls for real vigilance, with the major-rated entries the ones to understand first. Most of the list can shift how the body clears the drug: grapefruit can raise its levels while St.”

Reviewed by 2 · Jul 18, 2026

Open the Chlorpheniramine 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 Chlorpheniramine 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 Chlorpheniramine 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%

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

29 days ago today
Medication Chlorpheniramine
Steady interest

#1,923 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 Chlorpheniramine

What Is Chlorpheniramine Used For?

Brand names: Chlor-Trimeton, Teldrin

Chlorpheniramine is used to temporarily relieve common allergy symptoms caused by hay fever (allergic rhinitis) or other upper respiratory allergies. These include runny nose, sneezing, itchy or watery eyes, and itching of the nose or throat.

These uses are supported across multiple products — including tablets (such as Aller-chlor, Allergy, Allergy Relief, Allergy Time, Anti Allergy, and Chlorpheniramine Maleate), extended-release tablets (Allergy Relief and Chlorphen-12), the oral solution Ed Chlorped Jr, and the inhalers ClorRelief and ClorRelief KIDs.

See full Chlorpheniramine drug information
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
573Minor
1,967No known interaction
Moderate

289 interactions

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

Minor

573 interactions

Showing 60 of 573 minor interactions — see all 573 on the Hops page.

No interaction 1,967 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Hops and Chlorpheniramine Together: Common Questions

Can you take Hops with Chlorpheniramine?
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.
How serious is the Hops and Chlorpheniramine 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 Chlorpheniramine 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.