Drug & supplement interaction

Red Clover + Hydrochlorothiazide, Propranolol

Hydrochlorothiazide, Propranolol brand name: Inderide.

Minor Interaction
The bottom line Minor

Hydrochlorothiazide, Propranolol falls into 2 drug categories that Red Clover can interact with; the most serious is rated minor. Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.

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

Red Clover and Hydrochlorothiazide, Propranolol

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

Why Are There 2 Interactions?

Red Clover interacts with whole categories of medication. Hydrochlorothiazide, Propranolol falls into 2 of those categories, so it can interact with Red Clover 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 Hydrochlorothiazide, Propranolol

Hydrochlorothiazide, Propranolol falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Red Clover interacts with.

Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
In vitro evidence shows that red clover inhibits CYP1A2. However, a clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics 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

Inderide is a combo pill: hydrochlorothiazide (a water pill) plus propranolol (a beta-blocker). The propranolol part is partly handled by a liver enzyme called CYP1A2, and red clover might, in theory, slow that enzyme down. If that happened, propranolol levels could creep up a bit, which could mean more of its usual effects like a slower heart rate, lower blood pressure, tiredness, or feeling lightheaded.

Here's the reassuring part: this concern comes from lab dish studies only. When researchers actually gave people red clover isoflavones, it did not change how their bodies cleared a CYP1A2 test drug. So a real-world problem is unlikely. Still, if you notice unusual dizziness or a very slow pulse, check in with your pharmacist or doctor before changing anything.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Chen L, Choi J, Leonard SW, et al. No Clinically Relevant Pharmacokinetic Interactions of a Red Clover Dietary Supplement with Cytochrome P450 Enzymes in Women. J Agric Food Chem. 2020;68(47):13929-13939. PubMed
Minor

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

2 of 2

Hydrochlorothiazide, Propranolol also falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES.

Theoretically, red clover might increase the levels and clinical effects of drugs metabolized by CYP2C19.
In vitro evidence suggests that red clover weakly inhibits CYP2C19. This interaction has not been reported in humans.
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 honest picture with Inderide (a combination of hydrochlorothiazide and propranolol) and red clover. The concern on file is that red clover might block a liver enzyme called CYP2C19, which in theory could let certain drugs build up. But this is really weak, lab-dish only evidence, and it has never actually been seen in people. On top of that, propranolol is mostly handled by a different enzyme (CYP2D6), so 2C19 isn't its main exit route anyway.

If levels did nudge up, you might notice more of propranolol's usual effects, like a slower heartbeat, tiredness, or lightheadedness when standing. Realistically this is unlikely. Still, since red clover acts like a plant estrogen, it's worth a quick chat with your pharmacist or doctor before trying it.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 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

Red Clover Also Interacts With Other Medications

Red Clover has 44 moderate, 822 minor known drug interactions in our database — the Hydrochlorothiazide, Propranolol one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Red Clover

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

Everything else you take

See Every Supplement That Interacts With Hydrochlorothiazide, Propranolol

This page covers Red Clover only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Propranolol page lists 324 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 · 273 moderate · 40 minor.

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

“Inderide combines hydrochlorothiazide, a water pill, with propranolol, a beta blocker, so a supplement that also lowers blood pressure or pulls potassium out of the body hits the drug on its own turf. That describes most of this list, and I'd approach it with genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide, Propranolol interaction page

One more smart check

Taking Red Clover as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,480 real supplement products containing Red Clover, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Red Clover. Your product may carry other ingredients that interact with Hydrochlorothiazide, Propranolol too, on top of Red Clover — 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 Red Clover and Hydrochlorothiazide, Propranolol 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 Red Clover
Top 25%

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

29 days ago today
Medication Hydrochlorothiazide, Propranolol
Steady interest

#1,419 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 Red Clover

What is Red Clover?

Red Clover
  • Menopause symptoms (hot flashes)
  • High cholesterol
  • Bone health/osteoporosis
  • Skin and hair concerns
  • Women's health

Red clover is a plant rich in isoflavones (plant compounds with weak estrogen-like activity) that is most often used for menopause symptoms like hot flashes. The evidence is mixed and generally weak, with some studies showing modest benefit and others showing none. Because of its hormone-like effects, it's not for everyone—talk with your pharmacist or doctor before trying it, especially if you have a hormone-sensitive condition.

Read the full Red Clover monograph & all interactions
Keep checking

Other Drugs & Red Clover

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

0Major
44Moderate
822Minor
1,963No known interaction
Moderate

44 interactions

Minor

822 interactions

Showing 60 of 822 minor interactions — see all 822 on the Red Clover page.

No interaction 1,963 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 Red Clover and Hydrochlorothiazide, Propranolol Together: Common Questions

Can you take Red Clover with Hydrochlorothiazide, Propranolol?
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 Red Clover and Hydrochlorothiazide, Propranolol?
Hydrochlorothiazide, Propranolol belongs to more than one drug category, and Red Clover 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 Red Clover and Hydrochlorothiazide, Propranolol 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

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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.