Drug & supplement interaction

Uva Ursi + 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 3 drug categories that Uva Ursi can interact with; the most serious is rated moderate. Theoretically, uva ursi may decrease the metabolism of CYP3A4 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Uva Ursi and Conjugated Estrogens, Meprobamate

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

Why Are There 3 Interactions?

Uva Ursi interacts with whole categories of medication. Conjugated Estrogens, Meprobamate falls into 3 of those categories, so it can interact with Uva Ursi in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 3

Why this applies to Conjugated Estrogens, Meprobamate

Conjugated Estrogens, Meprobamate falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Uva Ursi interacts with.

Theoretically, uva ursi may decrease the metabolism of CYP3A4 substrates.
In vitro, uva ursi appears to inhibit CYP3A4. This effect has not been reported in humans.
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

Your medicine combines conjugated estrogens with meprobamate (a calming, anti-anxiety ingredient). Both pass through a liver enzyme called CYP3A4 to get cleared from your body. In lab dish studies, uva ursi seemed to slow that enzyme down. If that happened in real life, these medicines could build up a bit, which might mean more estrogen-related effects (breast tenderness, nausea, headaches, fluid retention) or extra drowsiness and grogginess from the meprobamate part.

Here's the honest part: this slowdown has only been seen in a test tube, never confirmed in people, so it's mostly theoretical. Uva ursi is also meant only for short-term use because of liver concerns. Before pairing the two, please check with your pharmacist or doctor so they can guide you safely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chauhan B, Yu C, Krantis A, et al. In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoprotein. Can J Physiol Pharmacol. 2007;85(11):1099-107.
Moderate

GLUCURONIDATED DRUGS

2 of 3

Conjugated Estrogens, Meprobamate also falls under GLUCURONIDATED DRUGS.

Theoretically, uva ursi may increase levels of drugs metabolized by glucuronidation.
In vitro, uva ursi extract appears to strongly inhibit UDP-glucuronosyltransferase (UGT) 1A1 (UGT1A1). However, uva ursi extract does not appear to inhibit UGT1A1 in animal models. This effect has not been reported in humans.
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 short version on combining uva ursi with PMB (which pairs conjugated estrogens with meprobamate). Your body clears the estrogen part partly through a process called glucuronidation. In a lab dish, uva ursi extract slowed one of those clearing enzymes (UGT1A1). If that happened in real life, estrogen levels could drift a little higher, which in theory might mean more breast tenderness, bloating, nausea, or spotting.

But I want to be honest about how thin this evidence is. This effect only showed up in test tubes. In animal studies it didn't pan out, and it has never been reported in actual people. So this is more theoretical than proven. Still, since uva ursi is meant for short-term use only, it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Park JB, Kim D, Min JS, et al. Identification and characterization of in vitro inhibitors against UDP-glucuronosyltransferase 1A1 in uva-ursi extracts and evaluation of in vivo uva-ursi-drug interactions. Food Chem Toxicol. 2018;120:651-661. PubMed
Minor

P-GLYCOPROTEIN SUBSTRATES

3 of 3

Conjugated Estrogens, Meprobamate also falls under P-GLYCOPROTEIN SUBSTRATES.

Theoretically, uva ursi may alter the levels of drugs transported by P-glycoprotein.
In vitro, uva ursi appears to inhibit the multi-drug transporter protein, P-glycoprotein. 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 with PMB, which combines conjugated estrogens with meprobamate (a mild sedative). In a lab dish, uva ursi seems to block a transporter called P-glycoprotein, which acts like a pump moving certain drugs around your body. If that pump slows down, in theory a bit more of a medication could stick around. For this combo, that might mean slightly stronger effects from the meprobamate piece, like extra drowsiness, dizziness, or feeling foggy.

The honest part: this is only a test-tube finding and has never been shown to happen in real people, so the risk is likely small. Still, since both ingredients can already cause sleepiness, it's worth a quick chat with your pharmacist or doctor before pairing them, especially since uva ursi is only meant for short-term use.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chauhan B, Yu C, Krantis A, et al. In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoprotein. Can J Physiol Pharmacol. 2007;85(11):1099-107.

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

Uva Ursi Also Interacts With Other Medications

Uva Ursi has 739 moderate, 63 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 739 Minor 63 No known interaction 2,028 (incl. Conjugated Estrogens, Meprobamate)
Taking anything else?

Check Another of Your Medications Against Uva Ursi

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

Everything else you take

See Every Supplement That Interacts With Conjugated Estrogens, Meprobamate

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

We hold 1,423 real supplement products containing Uva Ursi, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Uva Ursi. Your product may carry other ingredients that interact with Conjugated Estrogens, Meprobamate too, on top of Uva Ursi — 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 Uva Ursi 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 Uva Ursi
Top 25%

#169 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 Uva Ursi

What is Uva Ursi?

Uva Ursi
  • Urinary tract infections
  • Urinary discomfort
  • Mild diuretic
  • Kidney stones
  • Skin conditions

Uva ursi is a traditional herb used mainly for urinary tract infections, and its leaves contain a compound called arbutin that may have antimicrobial effects in the urine. Evidence in people is limited, and because high doses or long-term use may be harmful to the liver and could be toxic, it should only be used short-term and with guidance from a healthcare professional. Avoid it during pregnancy and breastfeeding.

Read the full Uva Ursi monograph & all interactions
Keep checking

Other Drugs & Uva Ursi

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

0Major
739Moderate
63Minor
2,027No known interaction
739 Moderate 63 Minor 2,027 No interaction
Moderate

739 interactions

Showing 60 of 739 moderate interactions — see all 739 on the Uva Ursi page.

Minor

63 interactions

Showing 60 of 63 minor interactions — see all 63 on the Uva Ursi page.

No interaction 2,027 drugs checked — show the list

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

Showing the 60 most looked-up of 2,027 medications checked with no known interaction — see the full Uva Ursi list.

See the full Uva Ursi 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
Uva Ursi 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 Uva Ursi and Conjugated Estrogens, Meprobamate Together: Common Questions

Can you take Uva Ursi 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 3 interactions listed for Uva Ursi and Conjugated Estrogens, Meprobamate?
Conjugated Estrogens, Meprobamate belongs to more than one drug category, and Uva Ursi 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 Uva Ursi 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.