Drug & supplement interaction

Garden Cress + Chlorthalidone

Chlorthalidone brand names: Hygroton, Thalitone.

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

Chlorthalidone 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 Chlorthalidone

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. Chlorthalidone 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 Chlorthalidone

Chlorthalidone 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

Here's the gist: chlorthalidone is a water pill that lowers your blood pressure by helping your body release extra salt and fluid. Garden cress, in animal studies, has shown its own mild blood-pressure-lowering effect. So the concern is that pairing the two could push your pressure down a little more than expected.

If that happens, you might feel lightheaded, dizzy, or shaky, especially when standing up quickly. I want to be honest, though: this is a theoretical worry based only on lab and animal research, and it hasn't been shown in people. Everyday food amounts of garden cress are very unlikely to cause trouble. Concentrated seed supplements are where I'd be more cautious. If you take them regularly, just keep an eye on your readings and check with your pharmacist or doctor.

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

Chlorthalidone 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

Here's the gist: chlorthalidone already nudges your kidneys to flush out water and potassium, which is why your doctor may keep an eye on your potassium levels. Garden cress, at least in animal studies, seems to act like a mild water pill too and can push out extra potassium. Stack the two and the worry is that potassium could dip a little lower than it should (what we call hypokalemia).

Low potassium can show up as muscle cramps, weakness, tiredness, or an irregular heartbeat. Now, the honest part: this is theoretical and based only on animal research, not people, so a sprinkle of garden cress in your salad is very unlikely to cause trouble. Concentrated seed supplements are the bigger question mark. If you're taking those regularly, just mention it to your pharmacist or doctor so they can check your potassium.

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 Chlorthalidone 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. Chlorthalidone)
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.

From our Q&A

Questions About Garden Cress or Chlorthalidone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Garden Cress or Chlorthalidone, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Chlorthalidone

This page covers Garden Cress only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorthalidone page lists 222 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), Dolomite (major) and Lithium (major).

By severity: 8 major · 190 moderate · 24 minor.

From our pharmacist’s overview on the Chlorthalidone page

“Chlorthalidone (Hygroton, Thalitone) lowers blood pressure by helping the kidneys shed salt and water, and that mechanism makes its supplement interactions worth genuine care. Most of the 222 ingredients on file either add to its blood-pressure-lowering effect or act as diuretics themselves, so pressure or potassium can fall further th…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorthalidone 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 Chlorthalidone 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 Chlorthalidone 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

#1,164 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Chlorthalidone
Steady interest

#1,582 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
Medication

About Chlorthalidone

What Is Chlorthalidone Used For?

Brand names: Hygroton, Thalitone

Chlorthalidone is used to treat high blood pressure (hypertension) in adults. Lowering blood pressure reduces the risk of serious cardiovascular events, especially strokes and heart attacks. It can be used alone or combined with other blood pressure medicines.

Chlorthalidone is also used as an add-on treatment for edema (fluid buildup) caused by heart failure, liver cirrhosis, and kidney conditions including nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. Thalitone is additionally indicated for edema associated with heart failure, liver cirrhosis, and renal disease including nephrotic syndrome.

See full Chlorthalidone drug information
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 Chlorthalidone, 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 Chlorthalidone supplement interactions › Every supplement checked against Chlorthalidone, ranked by severity Chlorthalidone drug information › The full plain-English guide to this medication 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 Chlorthalidone Together: Common Questions

Can you take Garden Cress with Chlorthalidone?
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 Chlorthalidone?
Chlorthalidone 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 Chlorthalidone 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 Chlorthalidone 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.