Drug & supplement interaction

Dendrobium + Trandolapril, Verapamil

Trandolapril, Verapamil brand name: Tarka.

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

Dendrobium has a minor interaction with Trandolapril, Verapamil. The dendrobium constituent dendrobine is reported to have hypotensive effects.

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

Dendrobium and Trandolapril, Verapamil

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

Minor

ANTIHYPERTENSIVE DRUGS

Why this applies to Trandolapril, Verapamil

Trandolapril, Verapamil falls under ANTIHYPERTENSIVE DRUGS — the group Dendrobium interacts with.

The dendrobium constituent dendrobine is reported to have hypotensive effects. Theoretically, combining dendrobium with antihypertensive drugs might increase the risk of hypotension; use with caution.
Severity Minor 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

Tarka pairs two blood pressure medicines in one pill: trandolapril (an ACE inhibitor) and verapamil (a calcium channel blocker). Both already work to relax your vessels and lower your numbers. The concern here is simple: a compound in Dendrobium called dendrobine may also nudge blood pressure down a little, so stacking it on top of Tarka could, in theory, drop your pressure more than expected.

I want to be honest that this is a theoretical caution based on how dendrobine behaves, not on real-world reports, so the actual risk is likely small. Still, if you notice dizziness, lightheadedness when standing, fatigue, or a slow heartbeat, those are worth watching. Please check with your pharmacist or doctor before adding Dendrobium, and don't change your Tarka on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Dr. Duke's Phytochemical and Ethnobotanical Databases. Available at: http://www.ars-grin.gov/duke/.

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

Dendrobium Also Interacts With Other Medications

Dendrobium has 461 moderate, 147 minor known drug interactions in our database — the Trandolapril, Verapamil one above is one of them. If you take anything else, check it against the full list below.

Moderate 461 Minor 147 No known interaction 2,222 (incl. Trandolapril, Verapamil)
Taking anything else?

Check Another of Your Medications Against Dendrobium

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

Everything else you take

See Every Supplement That Interacts With Trandolapril, Verapamil

This page covers Dendrobium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Trandolapril, Verapamil page lists 304 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 Beer (major).

By severity: 11 major · 250 moderate · 43 minor.

From our pharmacist’s overview on the Trandolapril, Verapamil page

“This is one of the supplement lists I would want a patient to read closely, not skim. Tarka combines trandolapril and verapamil to lower blood pressure, and most of these interactions pull on that same lever, either dropping pressure further than intended or working against the medicine altogether.”

Reviewed by 2 · Jul 18, 2026

Open the Trandolapril, Verapamil interaction page

One more smart check

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

We hold 117 real supplement products containing Dendrobium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dendrobium. Your product may carry other ingredients that interact with Trandolapril, Verapamil too, on top of Dendrobium — 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 Dendrobium and Trandolapril, Verapamil 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 Dendrobium
Top half

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

29 days ago today
Medication Trandolapril, Verapamil
Top 25%

#540 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 Dendrobium

What is Dendrobium?

  • Dry mouth and thirst
  • Supporting digestion
  • General tonic/vitality
  • Eye and skin health
  • Recovery after illness

Dendrobium is a group of orchids long used in traditional Chinese medicine, often to moisten the body and as a general tonic. Human evidence for its modern health claims is very limited, so it should be viewed as a traditional remedy rather than a proven treatment. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding because safety isn't known.

Read the full Dendrobium monograph & all interactions
Keep checking

Other Drugs & Dendrobium

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

0Major
461Moderate
147Minor
2,221No known interaction
461 Moderate 147 Minor 2,221 No interaction
Moderate

461 interactions

Showing 60 of 461 moderate interactions — see all 461 on the Dendrobium page.

Minor

147 interactions

Showing 60 of 147 minor interactions — see all 147 on the Dendrobium page.

No interaction 2,221 drugs checked — show the list

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

Showing the 60 most looked-up of 2,221 medications checked with no known interaction — see the full Dendrobium list.

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

Can you take Dendrobium with Trandolapril, Verapamil?
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 Dendrobium and Trandolapril, Verapamil 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

Still Have a Question About Trandolapril, Verapamil and Dendrobium?

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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.