Drug & supplement interaction

Garden Cress + Benzthiazide

Benzthiazide brand name: Exna.

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

Benzthiazide falls into 2 drug categories that Garden Cress can interact with; the most serious is rated moderate. Theoretically, taking garden cress with antihypertensive drugs might increase the risk of hypotension.

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

Garden Cress and Benzthiazide

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

Why Are There 2 Interactions?

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

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Benzthiazide

Benzthiazide falls under ANTIHYPERTENSIVE DRUGS — the group Garden Cress interacts with.

Theoretically, taking garden cress with antihypertensive drugs might increase the risk of hypotension.
Garden cress has shown hypotensive effects in animal research and increases levels and effects of the antihypertensive medications amlodipine and losartan. This has not been shown 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

Benzthiazide (Exna) is a thiazide-type water pill that lowers blood pressure by helping your body get rid of extra salt and fluid. Garden cress, in concentrated seed supplement form, has shown its own mild blood-pressure-lowering effect in animal studies. So the worry here is simple: stacking the two could push your blood pressure a little lower than expected.

If that happens, you might feel dizzy, lightheaded, tired, or wobbly when you stand up quickly. Keep in mind this is theoretical, based only on animal and lab research, and hasn't been confirmed in people. Cress used as food in cooking is very unlikely to matter. If you take daily cress seed supplements, just mention it to your pharmacist or doctor so they can keep an eye on your readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Maghrani, M, Zeggwagh, NA, Michel, JB, and Eddouks, M. Antihypertensive effect of <it>Lepidium sativum</it> L. in spontaneously hypertensive rats. Journal of Ethnopharmacology (Ireland) 2005;100:193-197.
  2. Bin Jardan YA, Ahad A, Raish M, Alam MA, Al-Mohizea AM, Al-Jenoobi FI. Effects of garden cress, fenugreek and black seed on the pharmacodynamics of metoprolol: an herb-drug interaction study in rats with hypertension. Pharm Biol 2021;59(1):1088-1097. PubMed
  3. Alam MA, Bin Jardan YA, Raish M, Al-Mohizea AM, Ahad A, Al-Jenoobi FI. Herb-drug interaction: pharmacokinetics and pharmacodynamics of anti-hypertensive drug amlodipine besylate in presence of Lepidium sativum and Curcuma longa. Xenobiotica 2022;52(2):177
  4. Ahad A, Raish M, Abdelrahman IA, et al. Changes in pharmacokinetics and pharmacodynamics of losartan in experimental diseased rats treated with Curcuma longa and Lepidium sativum. Pharmaceuticals (Basel) 2022;16(1):33. PubMed
Moderate

DIURETIC DRUGS

2 of 2

Benzthiazide also falls under DIURETIC DRUGS.

Theoretically, taking garden cress with diuretic drugs might increase the risk of hypokalemia.
Evidence from animal research suggests that garden cress has diuretic effects and can increase the urinary excretion of potassium. This has not been shown in humans. Initiation of potassium supplementation or an increase in potassium supplement dose may be necessary for some patients.
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

Benzthiazide (Exna) is a thiazide-type water pill, and one of its well-known quirks is that it makes you lose potassium in your urine. That can leave potassium running low, which may show up as muscle cramps, weakness, tiredness, or an irregular heartbeat. Here's the catch with garden cress: in animal studies it acted as a mild diuretic and pushed potassium out through the urine too. So in theory, stacking the two could add up and drop your potassium a little further.

I want to be honest about the strength of this, though. This effect has only been seen in animals, not in people, and a sprinkle of garden cress in a salad is very different from concentrated seed supplements. If you regularly use garden cress seed supplements, just mention it to your doctor or pharmacist so they can check your potassium. Please don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Maghrani, M, Zeggwagh, NA, Michel, JB, and Eddouks, M. Antihypertensive effect of <it>Lepidium sativum</it> L. in spontaneously hypertensive rats. Journal of Ethnopharmacology (Ireland) 2005;100:193-197.

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

Garden Cress Also Interacts With Other Medications

Garden Cress has 397 moderate known drug interactions in our database — the Benzthiazide one above is among them. If you take anything else, check it against the full list below.

Moderate 397 No known interaction 2,433 (incl. Benzthiazide)
Taking anything else?

Check Another of Your Medications Against Garden Cress

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

Everything else you take

See Every Supplement That Interacts With Benzthiazide

This page covers Garden Cress only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Benzthiazide 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 Benzthiazide page

“Benzthiazide (Exna), a thiazide water pill prescribed for high blood pressure and fluid retention, comes with a supplement list I would treat with genuine respect. Most of what appears here either drops blood pressure further than intended or deepens the potassium and fluid loss the drug already causes, and a handful can strain the kid…”

Reviewed by 2 · Jul 18, 2026

Open the Benzthiazide interaction page

One more smart check

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

We hold 16 real supplement products containing Garden Cress, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Garden Cress. Your product may carry other ingredients that interact with Benzthiazide too, on top of Garden Cress — 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 Garden Cress and Benzthiazide 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 Garden Cress
Steady interest

#1,371 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Benzthiazide
Top half

#1,004 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 Garden Cress

What is Garden Cress?

Garden Cress
  • Digestive support
  • Bone health
  • Iron and vitamin source
  • Cough and respiratory comfort
  • Boosting breast milk (traditional)
  • Constipation relief

Garden cress is a nutritious leafy herb and seed used widely in cooking and traditional medicine, providing vitamins, minerals, and fiber. While it has a long history of use for digestion, bone health, and lactation, strong human research supporting most medicinal claims is limited. It is generally safe as a food, but concentrated seed supplements should be used cautiously and avoided in pregnancy.

Read the full Garden Cress monograph & all interactions
Keep checking

Other Drugs & Garden Cress

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

0Major
397Moderate
0Minor
2,432No known interaction
397 Moderate 2,432 No interaction
Moderate

397 interactions

Showing 60 of 397 moderate interactions — see all 397 on the Garden Cress page.

No interaction 2,432 drugs checked — show the list

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

Showing the 60 most looked-up of 2,432 medications checked with no known interaction — see the full Garden Cress list.

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

Can you take Garden Cress with Benzthiazide?
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 Garden Cress and Benzthiazide?
Benzthiazide belongs to more than one drug category, and Garden Cress 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 Garden Cress and Benzthiazide 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 Benzthiazide and Garden Cress?

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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.