Drug & supplement interaction

Cilantro + Promethazine

Promethazine brand name: Phenergan.

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

Cilantro has a moderate interaction with Promethazine. Evidence from in vitro research suggests that coriandrin, a constituent of cilantro, has photosensitizing effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Cilantro and Promethazine

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

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Promethazine

Promethazine falls under PHOTOSENSITIZING DRUGS — the group Cilantro interacts with.

Evidence from in vitro research suggests that coriandrin, a constituent of cilantro, has photosensitizing effects. Theoretically, concomitant use with photosensitizing drugs might increase photosensitivity. Some drugs that cause photosensitivity include amitriptyline (Elavil), quinolones (Ciprofloxacin, others), sulfa drugs (Septra, Bactrim, others), and tetracycline.
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 deal with cilantro and promethazine (Phenergan). Promethazine can already make your skin more sensitive to sunlight, meaning you may sunburn faster than usual. Cilantro contains a compound called coriandrin that, in lab tests, also seems to make skin more reactive to UV light. Put them together and, in theory, you could be a little more prone to a sunburn or a rash from the sun.

I want to be honest though: this is a theoretical concern based on test-tube studies, not real patient cases. Normal amounts of cilantro in your food are very unlikely to matter. Concentrated cilantro supplements or essential oil are the bigger question mark. To play it safe, use sunscreen and limit strong sun while on promethazine, and ask your pharmacist if you have concerns.

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

Cilantro Also Interacts With Other Medications

Cilantro has 433 moderate known drug interactions in our database — the Promethazine one above is one of them. If you take anything else, check it against the full list below.

Moderate 433 No known interaction 2,397 (incl. Promethazine)
Taking anything else?

Check Another of Your Medications Against Cilantro

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

From our Q&A

Questions About Cilantro or Promethazine

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

This page covers Cilantro only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promethazine page lists 83 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 23 minor.

From our pharmacist’s overview on the Promethazine page

“Promethazine (Phenergan) is a phenothiazine antihistamine used for allergies, nausea, and motion sickness, and it is strongly anticholinergic on its own, causing dry mouth, blurred vision, drowsiness, and constipation. That is why the 83 supplements and herbs on this list deserve real attention, starting with the three rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Promethazine interaction page

How much people look this up

Where Cilantro and 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 Cilantro
Steady interest

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

29 days ago today
Medication Promethazine
Steady interest

#1,646 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 Cilantro

What is Cilantro?

  • Digestive upset and bloating
  • Antimicrobial support
  • Antioxidant support
  • Heavy metal 'detox' (chelation) claims
  • Culinary flavoring

Cilantro is the leafy part of the Coriandrum sativum plant and is widely eaten as a food, where it is considered safe for most people. While it has antioxidant and antimicrobial properties in lab studies, strong human evidence for any specific health benefit is lacking, and popular 'detox' claims are not well supported. Talk with your pharmacist or doctor before using concentrated cilantro supplements or essential oil.

Read the full Cilantro monograph & all interactions
Medication

About Promethazine

What Is Promethazine Used For?

Brand name: Phenergan

Promethazine is used for a wide range of conditions. Tablets, oral solution, and rectal suppositories (brands including Phenergan, Promethegan, and Phenadoz) are approved for seasonal and perennial allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, hives (urticaria), angioedema, dermographism, and allergic reactions to blood or plasma. They are also used for motion sickness (both prevention and active treatment), nausea and vomiting related to anesthesia and surgery, sedation, and as a helper medication alongside pain relievers after surgery.

Promethazine hydrochloride injection (brands including Phenergan and Promethazine HCl injection) is used for many of the same purposes but is reserved for situations where oral treatment is not possible — including allergic emergencies as an adjunct to epinephrine, sedation during labor, and as an aid during certain surgical procedures such as bronchoscopy and eye surgery.

See full Promethazine drug information
Keep checking

Other Drugs & Cilantro

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

0Major
433Moderate
0Minor
2,396No known interaction
433 Moderate 2,396 No interaction
Moderate

433 interactions

Showing 60 of 433 moderate interactions — see all 433 on the Cilantro page.

No interaction 2,396 drugs checked — show the list

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

Showing the 60 most looked-up of 2,396 medications checked with no known interaction — see the full Cilantro list.

See the full Cilantro interactions page
See every supplement checked against 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
Cilantro monograph › Uses, safety, and every drug interaction in one place Promethazine supplement interactions › Every supplement checked against Promethazine, ranked by severity Promethazine 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 Cilantro and Promethazine Together: Common Questions

Can you take Cilantro with 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.
How serious is the Cilantro and 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

Still Have a Question About Promethazine and Cilantro?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.