Drug & supplement interaction

Hops + Conjugated Estrogens, Meprobamate

Conjugated Estrogens, Meprobamate brand names: PMB 200, PMB 400.

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

Conjugated Estrogens, Meprobamate falls into 2 drug categories that Hops can interact with; the most serious is rated moderate. Theoretically, concomitant use of large amounts of hops might interfere with hormone replacement therapy due to competition for estrogen receptors.

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

Hops and Conjugated Estrogens, Meprobamate

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. Conjugated Estrogens, Meprobamate 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 (Moderate).

Moderate

ESTROGENS

1 of 2

Why this applies to Conjugated Estrogens, Meprobamate

Conjugated Estrogens, Meprobamate falls under ESTROGENS — the group Hops interacts with.

Theoretically, concomitant use of large amounts of hops might interfere with hormone replacement therapy due to competition for estrogen receptors.
In vitro research suggests that certain hops constituents can competitively bind to estrogen receptors. However, most hops extracts contain very small amounts of these constituents.
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

This product (PMB) pairs conjugated estrogens with meprobamate, and the part we're focused on here is the estrogen side. Hops contain a plant compound (8-prenylnaringenin) that can gently latch onto the same estrogen receptors your hormone therapy works through. In theory, large amounts of hops could compete for those spots and slightly blunt the benefit you're taking the estrogen for, like easing hot flashes or night sweats.

Here's the honest part: this concern comes only from lab studies, and most hops extracts contain very little of that active compound. So it's more of a 'good to know' than a red flag. Since hops can also add to drowsiness from meprobamate, just run any hops supplement by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs, and spices. Proc Soc Exp Biol Med 1998;217:369-78. PubMed
  2. Milligan SR, Kalita JC, Heyerick A, et al. Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beer. J Clin Endocrinol Metab 1999;84:2249-52.. PubMed
  3. Milligan SR, Kalita JC, Pocock V, et al. The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoids. J Clin Endocrinol Metab 2000;85:4912-5.. DOI
  4. Assessment report on Humulus lupulus L., flos. European Medicines Agency, 2014. Available at: https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-humulus-lupulus-l-flos_en.pdf. Accessed September 29, 2021.
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

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Conjugated Estrogens, Meprobamate 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 short version: this combination is very low on the worry list. The estrogen part of PMB is processed by a liver enzyme called CYP3A4, and there's a theory that hops might nudge that enzyme to work a little faster. If that happened, your estrogen could clear out slightly quicker, which in theory might soften its benefit for menopause symptoms like hot flashes.

But the real-world evidence is thin. It comes mostly from animal and lab studies, and a human study found only about an 8% change, too small to matter. The meprobamate (a mild sedative) plus hops, which can also cause drowsiness, is more worth noting, since you may feel extra sleepy. If you notice that, check in with your pharmacist or doctor.

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 288 moderate, 574 minor known drug interactions in our database — the Conjugated Estrogens, Meprobamate one above is among them. If you take anything else, check it against the full list below.

Moderate 288 Minor 574 No known interaction 1,968 (incl. Conjugated Estrogens, Meprobamate)
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 Conjugated Estrogens, Meprobamate

This page covers Hops only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Conjugated Estrogens, Meprobamate page lists 187 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 152 moderate · 32 minor.

From our pharmacist’s overview on the Conjugated Estrogens, Meprobamate page

“If you take conjugated estrogens with meprobamate (PMB), a combination that pairs hormone replacement with a sedative, treat this list as a real safety check, not background noise. Three of the 187 entries on file rate major, and they pull in different directions.”

Reviewed by 2 · Jul 18, 2026

Open the Conjugated Estrogens, Meprobamate 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 Conjugated Estrogens, Meprobamate 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 Conjugated Estrogens, Meprobamate 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 Conjugated Estrogens, Meprobamate
Steady interest

#2,131 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
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
288Moderate
574Minor
1,967No known interaction
288 Moderate 574 Minor 1,967 No interaction
Moderate

288 interactions

Showing 60 of 288 moderate interactions — see all 288 on the Hops page.

Minor

574 interactions

Showing 60 of 574 minor interactions — see all 574 on the Hops page.

No interaction 1,967 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 1,967 medications checked with no known interaction — see the full Hops list.

See the full Hops interactions page
See every supplement checked against Conjugated Estrogens, Meprobamate, 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 Conjugated Estrogens, Meprobamate supplement interactions › Every supplement checked against Conjugated Estrogens, Meprobamate, ranked by severity 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 Conjugated Estrogens, Meprobamate Together: Common Questions

Can you take Hops with Conjugated Estrogens, Meprobamate?
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 Hops and Conjugated Estrogens, Meprobamate?
Conjugated Estrogens, Meprobamate 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 Conjugated Estrogens, Meprobamate 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

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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.