Drug & supplement interaction

Cilantro + Fluorouracil

Fluorouracil brand names: Efudex, Tolak.

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

Cilantro has a moderate interaction with Fluorouracil. 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?
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Interaction report

Cilantro and Fluorouracil

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

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Fluorouracil

Fluorouracil 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 gist: fluorouracil (Efudex, Tolak) can make your skin more sensitive to sunlight, so you may sunburn faster or get redness and irritation more easily. Cilantro contains a compound called coriandrin that, in lab studies only, also seems to boost sun sensitivity. Stacked together, the worry is that your skin could react to the sun a bit more than usual.

I want to be honest about how weak this is. It's theoretical, based on test-tube research, not real patient reports, and everyday cilantro in your food is very unlikely to cause trouble. Concentrated cilantro supplements or essential oil are the bigger question mark. Either way, good sun protection matters on fluorouracil. Check with your doctor or pharmacist before using cilantro 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

Cilantro Also Interacts With Other Medications

Cilantro has 433 moderate known drug interactions in our database — the Fluorouracil 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. Fluorouracil)
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.

Everything else you take

See Every Supplement That Interacts With Fluorouracil

This page covers Cilantro only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluorouracil page lists 26 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Alfalfa (moderate), Angelica Archangelica (moderate), Arrach (moderate), Bergamot (moderate) and Bishop's Weed (moderate).

By severity: 23 moderate · 3 minor.

From our pharmacist’s overview on the Fluorouracil page

“If you are using fluorouracil cream (Efudex, Tolak) on sun-damaged skin, your skin is already primed to react to sunlight, and that is where most of its supplement interactions sit. Of the 26 ingredients on file, 20 can make skin more sun-sensitive on their own, chlorophyll, chlorella, and bergamot oil among them, so pairing one with t…”

Reviewed by 2 · Jul 18, 2026

Open the Fluorouracil interaction page

How much people look this up

Where Cilantro and Fluorouracil 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

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

29 days ago today
Medication Fluorouracil
Steady interest

#2,267 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 Fluorouracil Injection

What Is Fluorouracil Injection Used For?

Brand names: Efudex, Tolak

Fluorouracil Injection is used to treat four types of adenocarcinoma (a common form of cancer that begins in glandular cells): cancer of the colon and rectum, breast cancer, stomach (gastric) cancer, and pancreatic cancer.

It is nearly always given as part of a combination chemotherapy regimen alongside other cancer medicines, and the specific drugs paired with it depend on which cancer is being treated.

See full Fluorouracil Injection 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 Fluorouracil, 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 Fluorouracil supplement interactions › Every supplement checked against Fluorouracil, ranked by severity Fluorouracil Injection 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 Fluorouracil Together: Common Questions

Can you take Cilantro with Fluorouracil?
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 Fluorouracil 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 Fluorouracil and Cilantro?

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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.