Drug & supplement interaction

Canadian Hemp + Spironolactone

Spironolactone brand names: Aldactone, Spiroton, Carospir.

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

Canadian Hemp has a moderate interaction with Spironolactone. Canadian hemp contains cardiac glycosides.

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

Canadian Hemp and Spironolactone

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

Moderate

DIURETIC DRUGS

Why this applies to Spironolactone

Spironolactone falls under DIURETIC DRUGS — the group Canadian Hemp interacts with.

Canadian hemp contains cardiac glycosides. Theoretically, concomitant use of potassium depleting diuretics and Canadian hemp can increase the risk of cardiac glycoside toxicity due to potassium depletion. Some diuretics that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and others.
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 an interesting twist with this pairing. The original concern is about diuretics that lower potassium, because low potassium makes the heart more sensitive to the cardiac glycosides in Canadian Hemp, raising the risk of dangerous heart rhythm problems. But spironolactone (Aldactone, Carospir) works the opposite way. It's a potassium-sparing diuretic, meaning it actually holds onto potassium rather than flushing it out.

So the potassium-depletion worry doesn't really apply to spironolactone the way it does to drugs like furosemide or HCTZ. That said, Canadian Hemp itself is genuinely toxic and not something I'd ever recommend taking. Please skip it and talk with your pharmacist or doctor about safer, proven options for your heart or blood pressure.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Canadian Hemp Also Interacts With Other Medications

Canadian Hemp has 75 moderate known drug interactions in our database — the Spironolactone one above is one of them. If you take anything else, check it against the full list below.

Moderate 75 No known interaction 2,755 (incl. Spironolactone)
Taking anything else?

Check Another of Your Medications Against Canadian Hemp

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

From our Q&A

Questions About Canadian Hemp or Spironolactone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Canadian Hemp or Spironolactone, 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 Spironolactone

This page covers Canadian Hemp only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Spironolactone page lists 206 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), Lithium (major) and Oleander (major).

By severity: 7 major · 174 moderate · 25 minor.

From our pharmacist’s overview on the Spironolactone page

“Potassium is the supplement I check first for anyone on spironolactone (Aldactone, Carospir), because this water pill works by holding potassium in the body, and supplementing more on top of that can push blood levels too high. It is one of 206 supplement and herbal ingredients with documented interactions here, and the list warrants g…”

Reviewed by 2 · Jul 18, 2026

Open the Spironolactone interaction page

How much people look this up

Where Canadian Hemp and Spironolactone 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 Canadian Hemp
Steady interest

#1,026 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Spironolactone
Top 5%

#97 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 Canadian Hemp

What is Canadian Hemp?

  • Heart-related swelling (dropsy/edema)
  • Fluid retention
  • Constipation
  • Urinary problems
  • Traditional folk remedy uses

Canadian Hemp (Apocynum cannabinum) is a toxic North American plant historically used as a heart stimulant and diuretic, but it contains potent cardiac glycosides that can cause dangerous heart and poisoning effects. It is not a safe or recommended dietary supplement, and there is no reliable modern evidence supporting its use. Avoid using it and talk to a pharmacist or doctor about safer, proven options.

Read the full Canadian Hemp monograph & all interactions
Medication

About Spironolactone

What Is Spironolactone Used For?

Brand names: Aldactone, Spiroton, Carospir

Spironolactone tablets (including Aldactone) are used to treat moderate-to-severe heart failure, high blood pressure, and fluid retention (edema) caused by liver cirrhosis or nephrotic syndrome. They are also used to diagnose and manage primary hyperaldosteronism — a condition where the adrenal glands produce too much of the hormone aldosterone.

Spironolactone oral suspension shares several of these uses — heart failure, high blood pressure, and edema from liver cirrhosis — but is not the same as Aldactone and is not therapeutically interchangeable with it. Your prescriber will choose the right form for your situation.

See full Spironolactone drug information
Keep checking

Other Drugs & Canadian Hemp

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

0Major
75Moderate
0Minor
2,754No known interaction
75 Moderate 2,754 No interaction
Moderate

75 interactions

Showing 60 of 75 moderate interactions — see all 75 on the Canadian Hemp page.

No interaction 2,754 drugs checked — show the list

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

Showing the 60 most looked-up of 2,754 medications checked with no known interaction — see the full Canadian Hemp list.

See the full Canadian Hemp interactions page
See every supplement checked against Spironolactone, 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
Canadian Hemp monograph › Uses, safety, and every drug interaction in one place Spironolactone supplement interactions › Every supplement checked against Spironolactone, ranked by severity Spironolactone 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 Canadian Hemp and Spironolactone Together: Common Questions

Can you take Canadian Hemp with Spironolactone?
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.
How serious is the Canadian Hemp and Spironolactone 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 Spironolactone and Canadian Hemp?

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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.