Drug & supplement interaction

Centaury + Guanethidine Monosulfate

Guanethidine Monosulfate brand names: Ismelin, Isimil.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 27, 2026
The bottom line No known interaction

We found no known interaction between Centaury and Guanethidine Monosulfate in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Centaury and Guanethidine Monosulfate

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Guanethidine Monosulfate and Centaury in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Centaury at all — not against Guanethidine Monosulfate, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Centaury safety at a glance

Centaury overall Use caution Generally used in small amounts as a digestive bitter, but high-quality safety data are limited.
Pregnancy Avoid Not enough safety information; avoid use during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so it is best avoided.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Guanethidine Monosulfate and Centaury? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Everything else you take

See Every Supplement That Interacts With Guanethidine Monosulfate

This page covers Centaury only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guanethidine Monosulfate page lists 137 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), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 112 moderate · 21 minor.

From our pharmacist’s overview on the Guanethidine Monosulfate page

“Guanethidine monosulfate (Ismelin) is a forceful older drug for severe high blood pressure, and its interaction list warrants genuine care. Nearly all 137 supplements and herbs on file pull blood pressure one way or the other, either adding to the drug's effect and risking dizziness and faints, or pushing pressure back up and undoing t…”

Reviewed by 2 · Jul 18, 2026

Open the Guanethidine Monosulfate interaction page

One more smart check

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

We hold 67 real supplement products containing Centaury, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Centaury. Even though Centaury itself has no known interaction with Guanethidine Monosulfate, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Centaury and Guanethidine Monosulfate 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 Centaury
Steady interest

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

29 days ago today
Medication Guanethidine Monosulfate
Steady interest

#1,633 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Centaury reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Centaury and Guanethidine Monosulfate records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Centaury

What is Centaury?

  • Poor appetite
  • Indigestion and bloating
  • Stimulating digestion (bitter tonic)
  • Mild fever (traditional)
  • Liver and gallbladder support (traditional)

Centaury is a bitter-tasting herb traditionally used to stimulate appetite and ease mild digestive complaints. Solid human studies are lacking, so its benefits remain largely unproven, and it is best used short-term with guidance from a pharmacist or doctor.

Centaurium erythraea · Gentianaceae · Aerial parts (flowering tops, leaves, and stems) · Tea (infusion), tincture, liquid extract, capsules, and as an ingredient in herbal bitters

An interaction check asks whether these two react with each other — it does not ask whether Centaury is a good idea for someone in your situation. Here is what our Centaury record says about it on its own.

Centaury: dosing

There is no officially established standard dose for centaury. Traditional use generally involves small amounts of the dried herb prepared as a tea or a few drops of tincture taken before meals.Because products differ widely in strength and form, the safest approach is to follow the directions on the product label and not exceed the recommended amount. It is meant for short-term, occasional use rather than long-term daily use.

From our Centaury monograph — the full record covers uses, side effects and every documented interaction.

Read the full Centaury monograph & all interactions
Keep checking

Other Drugs & Centaury

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Centaury list.

See the full Centaury interactions page
See every supplement checked against Guanethidine Monosulfate, ranked by severity
Evidence & sources

Centaury References

The 1 references that drive our Centaury monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Martynyuk L, Martynyuk L, Ruzhitska O, Martynyuk O. Effect of the herbal combination Canephron N on diabetic nephropathy in patients with diabetes mellitus: results of a comparative cohort study. J Altern Complement Med. 2014;20(6):472-478. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Centaury and Guanethidine Monosulfate Together: Common Questions

Is it safe to take Centaury with Guanethidine Monosulfate?
We do not list a known interaction between Centaury and Guanethidine Monosulfate. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Guanethidine Monosulfate interact with any supplements?
Yes. Guanethidine Monosulfate has documented interactions with 137 supplements in our database — Centaury is not one of them. The Guanethidine Monosulfate interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Centaury monograph Uses, safety profile, and every drug interaction in one place Guanethidine Monosulfate supplement interactions Every supplement checked against Guanethidine Monosulfate, 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 References The 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Guanethidine Monosulfate and Centaury?

Our pharmacists answer your medication & supplement questions — free.

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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.