Drug & supplement interaction

Coriander + Polythiazide, Reserpine

Polythiazide, Reserpine brand name: Renese R.

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

Polythiazide, Reserpine falls into 2 drug categories that Coriander can interact with; the most serious is rated moderate. Theoretically, coriander might increase the risk of hypotension when taken with antihypertensive drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Coriander and Polythiazide, Reserpine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Coriander interacts with whole categories of medication. Polythiazide, Reserpine falls into 2 of those categories, so it can interact with Coriander 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 Polythiazide, Reserpine

Polythiazide, Reserpine falls under ANTIHYPERTENSIVE DRUGS — the group Coriander interacts with.

Theoretically, coriander might increase the risk of hypotension when taken with antihypertensive drugs.
Evidence from animal research suggests that coriander fruit can lower blood pressure.
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

Renese R is a two-in-one blood pressure pill: polythiazide (a water pill) plus reserpine, which calms overactive nerve signals to the heart and vessels. Both already work to bring your numbers down. Coriander, mostly from animal studies, seems to have a mild blood-pressure-lowering effect of its own.

So the concern here is simple: stacking coriander on top of this medicine could, in theory, push your pressure a little too low. That might show up as dizziness, lightheadedness, feeling faint when you stand up, or unusual tiredness. Keep in mind this is theoretical and the cooking amounts in your food are very unlikely to matter. Concentrated extracts or essential oils are a different story. If you're considering those, please run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Jabeen, Q., Bashir, S., Lyoussi, B., and Gilani, A. H. Coriander fruit exhibits gut modulatory, blood pressure lowering and diuretic activities. J Ethnopharmacol. 2-25-2009;122(1):123-130. PubMed
Moderate

PHOTOSENSITIZING DRUGS

2 of 2

Polythiazide, Reserpine also falls under PHOTOSENSITIZING DRUGS.

Theoretically, coriander might increase the risk of photosensitivity when taken with photosensitizing drugs.
Evidence from in vitro research suggests that coriandrin, a constituent of coriander, has photosensitizing effects.
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 for your Renese R, which combines polythiazide (a water pill) and reserpine. Water pills like polythiazide are already known to make some people's skin more sensitive to sunlight, so they sunburn faster than usual. Coriander may add a small bit to that, because one of its plant compounds (coriandrin) has shown light-sensitizing activity in lab dishes.

I want to be honest: this is a theoretical concern based on weak, test-tube evidence, not strong human studies. The cilantro on your tacos is very unlikely to cause trouble. Concentrated coriander extracts or essential oils are the bigger question mark. Either way, smart sun habits (sunscreen, a hat) cover you. Chat with your pharmacist if you plan to use coriander supplements.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ashwood-Smith, M. J., Warrington, P. J., Jenkins, M., Ceska, O., and Romaniuk, P. J. Photobiological properties of a novel, naturally occurring furoisocoumarin, coriandrin. Photochem.Photobiol. 1989;50(6):745-751. PubMed

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

Coriander Also Interacts With Other Medications

Coriander has 716 moderate known drug interactions in our database — the Polythiazide, Reserpine one above is among them. If you take anything else, check it against the full list below.

Moderate 716 No known interaction 2,114 (incl. Polythiazide, Reserpine)
Taking anything else?

Check Another of Your Medications Against Coriander

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

Everything else you take

See Every Supplement That Interacts With Polythiazide, Reserpine

This page covers Coriander only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Polythiazide, Reserpine page lists 228 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 · 193 moderate · 25 minor.

From our pharmacist’s overview on the Polythiazide, Reserpine page

“American hellebore is the ingredient I would keep farthest from polythiazide with reserpine (Renese R), a combination pill prescribed to lower blood pressure. Its alkaloids can drop pressure and slow the heart even at small doses, and it is one of ten major-rated entries among the 228 on file here, which puts this list in the take-it-s…”

Reviewed by 2 · Jul 18, 2026

Open the Polythiazide, Reserpine interaction page

One more smart check

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

We hold 934 real supplement products containing Coriander, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coriander. Your product may carry other ingredients that interact with Polythiazide, Reserpine too, on top of Coriander — 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 Coriander and Polythiazide, Reserpine 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 Coriander
Top 25%

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

29 days ago today
Medication Polythiazide, Reserpine
Steady interest

#2,189 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 Coriander

What is Coriander?

Coriander
  • Digestive upset and gas
  • Appetite stimulation
  • Mild antimicrobial (topical)
  • Diarrhea and IBS symptoms
  • General flavoring and traditional remedy

Coriander (also called cilantro) is a common cooking herb and spice that has long been used in traditional medicine for digestive complaints. As a food it is generally safe for most people, but high-quality human studies supporting its medicinal benefits are limited. Talk with your pharmacist or doctor before using concentrated extracts or essential oils.

Read the full Coriander monograph & all interactions
Keep checking

Other Drugs & Coriander

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

0Major
716Moderate
0Minor
2,113No known interaction
716 Moderate 2,113 No interaction
Moderate

716 interactions

Showing 60 of 716 moderate interactions — see all 716 on the Coriander page.

No interaction 2,113 drugs checked — show the list

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

Showing the 60 most looked-up of 2,113 medications checked with no known interaction — see the full Coriander list.

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

Can you take Coriander with Polythiazide, Reserpine?
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 Coriander and Polythiazide, Reserpine?
Polythiazide, Reserpine belongs to more than one drug category, and Coriander 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 Coriander and Polythiazide, Reserpine 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

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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.