Drug & supplement interaction

Coriander + Meperidine, Promethazine

Meperidine, Promethazine brand names: Meprozine, Mepergan.

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

Meperidine, Promethazine falls into 2 drug categories that Coriander can interact with; the most serious is rated moderate. Theoretically, coriander might cause additive sedative effects when taken with CNS depressants.

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

Coriander and Meperidine, Promethazine

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. Meperidine, Promethazine 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

CNS DEPRESSANTS

1 of 2

Why this applies to Meperidine, Promethazine

Meperidine, Promethazine falls under CNS DEPRESSANTS — the group Coriander interacts with.

Theoretically, coriander might cause additive sedative effects when taken with CNS depressants.
Evidence from animal research suggests that coriander fruit extract has sedative 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

This combination product pairs meperidine (a strong opioid pain reliever) with promethazine (an antihistamine that already causes drowsiness). On its own, this medicine tends to make people sleepy, foggy, and slow to react. The concern here is simple: animal studies hint that coriander may have mild calming or sedative effects of its own, so in theory it could pile on top of the sleepiness this drug already brings.

Keep in mind this is a theoretical concern based only on animal research, not human studies. The cilantro you sprinkle on tacos or soup is very unlikely to matter. Concentrated coriander extracts or essential oils are the bigger question mark. If you use those, mention it to your pharmacist or doctor, and watch for extra drowsiness, dizziness, or slowed breathing.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Emamghoreishi, M., Khasaki, M., and Aazam, M. F. Coriandrum sativum: evaluation of its anxiolytic effect in the elevated plus-maze. J Ethnopharmacol. 1-15-2005;96(3):365-370. PubMed
Moderate

PHOTOSENSITIZING DRUGS

2 of 2

Meperidine, Promethazine 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 this combo. Promethazine, one of the ingredients in Meprozine and Mepergan, can make your skin more sensitive to sunlight on its own. Coriander adds a small theoretical layer on top of that. Lab studies (not human ones) suggest a coriander compound called coriandrin may also react with sunlight. So in theory, pairing the two could nudge up your odds of sunburn, redness, or a rash after time outdoors.

I want to be honest though: this is weak, anecdotal evidence, and the cilantro in your tacos is very unlikely to cause trouble. Concentrated coriander extracts or oils are a bigger question mark. If you take this medication, just use sunscreen and cover up in strong sun, and check with your pharmacist before starting any coriander supplement.

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 Meperidine, Promethazine 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. Meperidine, Promethazine)
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 Meperidine, Promethazine

This page covers Coriander only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Meperidine, Promethazine page lists 207 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Henbane (major).

By severity: 10 major · 160 moderate · 37 minor.

From our pharmacist’s overview on the Meperidine, Promethazine page

“Meprozine combines meperidine, an opioid painkiller, with promethazine, a sedating antihistamine, so it already slows the brain on two fronts. I would read this list of 207 supplements and herbal ingredients with genuine care, starting with the 10 rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Meperidine, Promethazine 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 Meperidine, Promethazine 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 Meperidine, Promethazine 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%

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

29 days ago today
Medication Meperidine, Promethazine
Top 25%

#447 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 Meperidine, Promethazine, 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 Meperidine, Promethazine supplement interactions › Every supplement checked against Meperidine, Promethazine, 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 Meperidine, Promethazine Together: Common Questions

Can you take Coriander with Meperidine, Promethazine?
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 Meperidine, Promethazine?
Meperidine, Promethazine 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 Meperidine, Promethazine 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.