Drug & supplement interaction

Swamp Milkweed + Hydrochlorothiazide, Lisinopril

Hydrochlorothiazide, Lisinopril brand names: Zestoretic, Prinzide.

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

Swamp Milkweed has a moderate interaction with Hydrochlorothiazide, Lisinopril. Theoretically, potassium depleting diuretics might increase the risk of toxicity with swamp milkweed.

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

Swamp Milkweed and Hydrochlorothiazide, Lisinopril

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

Moderate

DIURETIC DRUGS

Why this applies to Hydrochlorothiazide, Lisinopril

Hydrochlorothiazide, Lisinopril falls under DIURETIC DRUGS — the group Swamp Milkweed interacts with.

Theoretically, potassium depleting diuretics might increase the risk of toxicity with swamp milkweed.
Swamp milkweed contains cardioactive steroids known as cardenolides that may have digitalis-like activity. Potassium depletion can increase the risk of cardenolide toxicity.
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 concern with this combo. Your blood pressure pill, Zestoretic, contains hydrochlorothiazide, a water pill that can flush out potassium along with extra fluid. Swamp Milkweed contains heart-acting compounds (cardenolides) that behave a bit like the old heart drug digitalis. When your body's potassium runs low, those milkweed compounds can become more toxic to the heart, which may lead to an irregular or unsafe heartbeat, nausea, or dizziness.

Keep in mind this is theoretical, based on how these substances work rather than on real human studies. Honestly, Swamp Milkweed is a toxic garden plant, not a proven supplement, so I wouldn't take it at all. Please don't change your blood pressure medication on your own. If you've been using milkweed in any form, check in with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 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

Swamp Milkweed Also Interacts With Other Medications

Swamp Milkweed has 3 major, 152 moderate known drug interactions in our database — the Hydrochlorothiazide, Lisinopril one above is one of them. If you take anything else, check it against the full list below.

Major 3 Moderate 152 No known interaction 2,675 (incl. Hydrochlorothiazide, Lisinopril)
Taking anything else?

Check Another of Your Medications Against Swamp Milkweed

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

Everything else you take

See Every Supplement That Interacts With Hydrochlorothiazide, Lisinopril

This page covers Swamp Milkweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Lisinopril page lists 236 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 · 199 moderate · 27 minor.

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

“I would not add a supplement casually alongside hydrochlorothiazide and lisinopril (Zestoretic, Prinzide). This combination lowers blood pressure with a water pill plus an ACE inhibitor, and most interacting ingredients either drag pressure down too far or push back against the drug, while smaller groups strain the kidneys, drain potas…”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide, Lisinopril interaction page

How much people look this up

Where Swamp Milkweed and Hydrochlorothiazide, Lisinopril 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 Swamp Milkweed
Top half

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

29 days ago today
Medication Hydrochlorothiazide, Lisinopril
Top 25%

#486 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 Swamp Milkweed

What is Swamp Milkweed?

  • Traditional digestive remedy
  • Diuretic (increasing urine)
  • Cough and respiratory complaints
  • Worm or parasite remedy (folk use)
  • Pollinator/garden plant rather than medicine

Swamp Milkweed is a native North American wetland plant best known today as a butterfly and pollinator garden plant, not a proven medicine. It contains toxic milky sap with cardiac glycoside-like compounds, and there is very little reliable human research to support any health use. Because of its potential toxicity, it should not be used as a supplement without professional guidance.

Read the full Swamp Milkweed monograph & all interactions
Medication

About Lisinopril and Hydrochlorothiazide

What Is Lisinopril and Hydrochlorothiazide Used For?

Brand names: Zestoretic, Prinzide

Lisinopril and hydrochlorothiazide tablets — sold under the brand name Zestoretic and as the generic combination — are used to treat high blood pressure (hypertension). Lowering blood pressure reduces the risk of serious cardiovascular events, including strokes and heart attacks.

This combination is not intended as a first-line starting treatment. It is typically used when a single blood pressure medication alone has not been enough to reach target blood pressure goals.

See full Lisinopril and Hydrochlorothiazide drug information
Keep checking

Other Drugs & Swamp Milkweed

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

3Major
152Moderate
0Minor
2,674No known interaction
3 Major 152 Moderate 2,674 No interaction
Major

3 interactions

Moderate

152 interactions

Showing 60 of 152 moderate interactions — see all 152 on the Swamp Milkweed page.

No interaction 2,674 drugs checked — show the list

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

Showing the 60 most looked-up of 2,674 medications checked with no known interaction — see the full Swamp Milkweed list.

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

Can you take Swamp Milkweed with Hydrochlorothiazide, Lisinopril?
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 Swamp Milkweed and Hydrochlorothiazide, Lisinopril 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 Hydrochlorothiazide, Lisinopril and Swamp Milkweed?

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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.