Drug & supplement interaction

Banderol + Hydrochlorothiazide, Metoprolol

Hydrochlorothiazide, Metoprolol brand name: Lopressor HCT.

Moderate Interaction
Medically reviewed by · Updated February 2023
The bottom line Moderate

Hydrochlorothiazide, Metoprolol falls into 2 drug categories that Banderol can interact with; the most serious is rated moderate. Small lab studies have found that Banderol may inhibit OATP1B1 (Organic Anion Transporting Polypeptide 1B1), which is a membrane protein responsible for the uptake of various drugs, hormones, and other biologically active substances into the cells of the liver and other tissues.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceA
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Banderol and Hydrochlorothiazide, Metoprolol

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

Why Are There 2 Interactions?

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

Moderate

ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES

1 of 2

Why this applies to Hydrochlorothiazide, Metoprolol

Hydrochlorothiazide, Metoprolol falls under ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES — the group Banderol interacts with.

Small lab studies have found that Banderol may inhibit OATP1B1 (Organic Anion Transporting Polypeptide 1B1), which is a membrane protein responsible for the uptake of various drugs, hormones, and other biologically active substances into the cells of the liver and other tissues. It is often referred to as a drug transporter. It is a member of the OATP family of transporters and is known to play a critical role in the pharmacokinetics of many drugs. When OATPs are inhibited, it can cause problems with the elimination of drugs and result in a sudden rise in the concentration of the drug in the bloodstream and the extent to which it is absorbed (AUC) for drugs that rely on these transporters. This can increase the likelihood of adverse side effects associated with the therapy.
Severity Moderate Likelihood Possible Evidence A

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 your Lopressor HCT (which combines metoprolol, a beta-blocker, with hydrochlorothiazide, a water pill). Lab studies suggest Banderol may slow down a liver transporter called OATP1B1. If that transporter gets blocked, drugs that rely on it can clear more slowly and build up a bit in your bloodstream, which could nudge their effects upward.

In real life, that might mean a stronger blood-pressure-lowering punch than expected, with possible dizziness, lightheadedness, tiredness, or a slower heart rate from the metoprolol side. Keep in mind this is based on test-tube data, not solid human studies, so it's a theoretical concern rather than a sure thing. Still, since these are heart and blood pressure meds, please run it by your pharmacist or doctor before adding Banderol.

Contact Dr. Brian directly if you have additional questions on this interaction
Moderate

ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES

2 of 2

Hydrochlorothiazide, Metoprolol also falls under ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES.

Small lab studies have found that Banderol may also inhibit OATP1B3 (Organic Anion Transporting Polypeptide 1B3), in addition to OATP1B1. If a drug is a substrate for both transporters, the risk of interaction with Banderol increases but the overall clinical significance is not well understood.
Severity Moderate Likelihood Possible Evidence A

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

If you're taking Lopressor HCT (the combo of hydrochlorothiazide, a water pill, and metoprolol, a beta-blocker for blood pressure), here's the honest picture. The interaction on file comes from small test-tube studies suggesting Banderol may block certain liver transporters (OATP1B1 and OATP1B3). The idea is that if a drug relies on those transporters, blocking them could let a bit more of it linger in your system.

In real life, this is mostly theoretical, and how much it matters in people isn't well understood. If levels did nudge up, you might notice things like extra dizziness, a slower heartbeat, or feeling unusually tired from the metoprolol. Because Banderol itself has weak evidence behind it, please don't change either medication on your own. Just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction

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

Banderol Also Interacts With Other Medications

Banderol has 176 moderate known drug interactions in our database — the Hydrochlorothiazide, Metoprolol one above is among them. If you take anything else, check it against the full list below.

Moderate 176 No known interaction 2,654 (incl. Hydrochlorothiazide, Metoprolol)
Taking anything else?

Check Another of Your Medications Against Banderol

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

Everything else you take

See Every Supplement That Interacts With Hydrochlorothiazide, Metoprolol

This page covers Banderol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Metoprolol page lists 276 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Dolomite (major).

By severity: 11 major · 235 moderate · 30 minor.

From our pharmacist’s overview on the Hydrochlorothiazide, Metoprolol page

“I would treat this list with genuine care. Lopressor HCT combines hydrochlorothiazide, a diuretic, with metoprolol, a beta-blocker, and 276 supplement and herbal ingredients interact with the pair, 11 of them rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide, Metoprolol interaction page

How much people look this up

Where Banderol and Hydrochlorothiazide, Metoprolol 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 Banderol
Steady interest

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

29 days ago today
Medication Hydrochlorothiazide, Metoprolol
Top half

#818 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 Banderol

What is Banderol?

Banderol
  • Lyme disease support
  • Antimicrobial
  • Antifungal
  • Immune support
  • Inflammation

Banderol is a Nutramedix-branded herbal extract made from the bark of the Amazonian tree Otoba parvifolia, most often promoted as part of alternative Lyme disease protocols. There is very little high-quality human research to support its use, so the evidence behind its benefits is weak and largely preliminary. Talk with your pharmacist or doctor before using it, and never use it to replace proven treatments.

Read the full Banderol monograph & all interactions
Keep checking

Other Drugs & Banderol

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

0Major
176Moderate
0Minor
2,653No known interaction
176 Moderate 2,653 No interaction
Moderate

176 interactions

Showing 60 of 176 moderate interactions — see all 176 on the Banderol page.

No interaction 2,653 drugs checked — show the list

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

Showing the 60 most looked-up of 2,653 medications checked with no known interaction — see the full Banderol list.

See the full Banderol interactions page
See every supplement checked against Hydrochlorothiazide, Metoprolol, 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
Banderol monograph › Uses, safety, and every drug interaction in one place Hydrochlorothiazide, Metoprolol supplement interactions › Every supplement checked against Hydrochlorothiazide, Metoprolol, 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 Banderol and Hydrochlorothiazide, Metoprolol Together: Common Questions

Can you take Banderol with Hydrochlorothiazide, Metoprolol?
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 Banderol and Hydrochlorothiazide, Metoprolol?
Hydrochlorothiazide, Metoprolol belongs to more than one drug category, and Banderol 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 Banderol and Hydrochlorothiazide, Metoprolol 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 Hydrochlorothiazide, Metoprolol and Banderol?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.