Drug & supplement interaction

Fenugreek + Polythiazide

Polythiazide brand name: Renese.

Minor Interaction
The bottom line Minor

Fenugreek has a minor interaction with Polythiazide. Fenugreek may also have an additive effect on blood pressure-lowering medications.

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

Fenugreek and Polythiazide

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

Minor

Antihypertensive Drugs

Why this applies to Polythiazide

Polythiazide falls under Antihypertensive Drugs — the group Fenugreek interacts with.

Fenugreek may also have an additive effect on blood pressure-lowering medications. Studies on animals have shown that fenugreek seed can decrease both systolic and diastolic blood pressure by up to 22% when combined with metoprolol. Therefore, it is essential to monitor your blood pressure regularly if you are taking fenugreek and metoprolol together or any other antihypertensive drugs.
Severity Minor Likelihood Possible Evidence C

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

Polythiazide (Renese) is a thiazide-type water pill that lowers blood pressure by helping your body get rid of extra salt and fluid. Fenugreek, when taken in concentrated supplement doses, may have its own mild blood pressure lowering effect. Stack the two together and that effect could add up, so your pressure might drop a little more than expected.

If that happens, you could feel lightheaded, dizzy, or tired, especially when you stand up quickly. Honestly, the evidence here is thin and mostly from animal studies, so this is a possible, minor concern rather than a strong warning. Sprinkling fenugreek on your food is very unlikely to matter. If you take it as a supplement, just check your blood pressure regularly and mention it to your pharmacist or doctor.

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

Fenugreek Also Interacts With Other Medications

Fenugreek has 224 moderate, 164 minor known drug interactions in our database — the Polythiazide 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 Fenugreek

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

Everything else you take

See Every Supplement That Interacts With Polythiazide

This page covers Fenugreek only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Polythiazide page lists 227 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: 10 major · 192 moderate · 25 minor.

From our pharmacist’s overview on the Polythiazide page

“Polythiazide (Renese) is a thiazide diuretic for high blood pressure, and this is a list I would treat with real care. Most entries either add to its blood-pressure-lowering and fluid-losing effects or deepen the potassium loss it already causes, which can leave someone dizzy or set the stage for heart rhythm trouble.”

Reviewed by 2 · Jul 18, 2026

Open the Polythiazide interaction page

One more smart check

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

We hold 2,385 real supplement products containing Fenugreek, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fenugreek. Your product may carry other ingredients that interact with Polythiazide too, on top of Fenugreek — 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 Fenugreek and Polythiazide 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 Fenugreek
Top 10%

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

29 days ago today
Medication Polythiazide
Top half

#845 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 Fenugreek

What is Fenugreek?

Fenugreek
  • Blood sugar control
  • Boosting breast milk supply
  • High cholesterol
  • Digestive upset
  • Low testosterone or libido

Fenugreek is a common kitchen spice that is also taken as a supplement, mainly for blood sugar, cholesterol, and to support breast milk production. Some early research is encouraging for blood sugar, but overall the evidence is mixed and far from settled. It is generally well tolerated as food, but talk with your pharmacist or doctor before using it as a supplement, especially if you are pregnant.

Read the full Fenugreek monograph & all interactions
Keep checking

Other Drugs & Fenugreek

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

0Major
224Moderate
164Minor
2,441No known interaction
Moderate

224 interactions

Showing 60 of 224 moderate interactions — see all 224 on the Fenugreek page.

Minor

164 interactions

Showing 60 of 164 minor interactions — see all 164 on the Fenugreek page.

No interaction 2,441 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 Fenugreek and Polythiazide Together: Common Questions

Can you take Fenugreek with Polythiazide?
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 Fenugreek and Polythiazide 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.