Drug & supplement interaction

Coriander + Guanfacine

Guanfacine brand name: Tenex.

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

Coriander has a moderate interaction with Guanfacine. Theoretically, coriander might increase the risk of hypotension when taken with antihypertensive drugs.

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

Coriander and Guanfacine

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Guanfacine

Guanfacine 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

Here's the simple version: guanfacine already works by lowering your blood pressure and slowing your heart rate a bit. Coriander, at least in animal studies, may nudge blood pressure down too. Put them together and the worry is that those two effects could stack, leaving you a little lower than expected. With guanfacine that might show up as feeling dizzy or lightheaded (especially when standing up), unusually tired, or a slower pulse.

I want to be honest about the strength of this, though. This is mostly theoretical, based on animal research, not solid human trials. The cilantro you sprinkle on tacos almost certainly won't do anything. Concentrated coriander extracts or essential oils are where I'd be more cautious. If you use those, just give your pharmacist or doctor a heads-up.

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

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 Guanfacine one above is one of them. If you take anything else, check it against the full list below.

Moderate 716 No known interaction 2,114 (incl. Guanfacine)
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.

From our Q&A

Questions About Coriander or Guanfacine

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

This page covers Coriander only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guanfacine page lists 136 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 · 111 moderate · 21 minor.

Open the Guanfacine 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 Guanfacine 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 Guanfacine 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%

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

29 days ago today
Medication Guanfacine
Top half

#975 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
Medication

About Guanfacine

What Is Guanfacine Used For?

Brand name: Tenex

Guanfacine immediate-release tablets (Guanfacine, Guanfacine Hydrochloride) are used to manage high blood pressure (hypertension). They can be used alone or together with other blood pressure medicines, especially thiazide-type diuretics (water pills).

Guanfacine extended-release tablets — sold as Guanfacine ER, Guanfacine extended-release, and Intuniv — are approved for the treatment of ADHD in children and adolescents ages 6 to 17. They can be used on their own (monotherapy) or alongside stimulant ADHD medications as add-on therapy.

See full Guanfacine drug information
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 Guanfacine, 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 Guanfacine supplement interactions › Every supplement checked against Guanfacine, ranked by severity Guanfacine 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 Coriander and Guanfacine Together: Common Questions

Can you take Coriander with Guanfacine?
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 Coriander and Guanfacine 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 Guanfacine and Coriander?

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.