Drug & supplement interaction

Chlorophyll + Fluorouracil

Fluorouracil brand names: Efudex, Tolak.

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

Chlorophyll has a moderate interaction with Fluorouracil. Theoretically, concomitant use of chlorophyll with photosensitizing drugs may have additive effects.

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

Chlorophyll 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 Chlorophyll interacts with.

Theoretically, concomitant use of chlorophyll with photosensitizing drugs may have additive effects.
Chlorophyll has been reported to cause photosensitization. In two case reports, pseudoporphyria developed after oral intake of chlorophyll. Theoretically, concomitant use with other photosensitizing drugs may exacerbate this effect.
Severity Moderate Likelihood Probable Evidence B

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to know about combining chlorophyll with fluorouracil: both can make your skin more sensitive to sunlight. Fluorouracil, whether you're using the topical cream (Efudex, Tolak) or getting the IV form for cancer, is well known for causing sun sensitivity, so you can sunburn faster and end up with more redness, blistering, or irritation. Chlorophyll has its own reports of photosensitivity, so stacking the two could in theory add up and make your skin react more strongly.

I'll be honest, this concern is mostly theoretical and based on a couple of case reports, not strong studies. Still, it's an easy one to play it safe with. Be diligent about sunscreen, hats, and covering up, and check with your oncologist or pharmacist before adding a chlorophyll supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mathews-Roth MM. Carotenoids in erythropoietic protoporphyria and other photosensitivity diseases. Ann N Y Acad Sci, 1993; 691:127-38. PubMed
  2. Rossi E, Borchard K, Cole JM. Pseudoporphyria following self-medication with chlorophyll. Australas J Dermatol. 2015 Feb;56(1):47-8. 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

Chlorophyll Also Interacts With Other Medications

Chlorophyll has 336 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 336 No known interaction 2,494 (incl. Fluorouracil)
Taking anything else?

Check Another of Your Medications Against Chlorophyll

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

From our Q&A

Questions About Chlorophyll or Fluorouracil

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

This page covers Chlorophyll 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

One more smart check

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

We hold 996 real supplement products containing Chlorophyll, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chlorophyll. Your product may carry other ingredients that interact with Fluorouracil too, on top of Chlorophyll — 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 Chlorophyll 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 Chlorophyll
Top 25%

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

29 days ago today
Medication Fluorouracil
Steady interest

#2,170 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 Chlorophyll

What is Chlorophyll?

Chlorophyll
  • Body and breath odor reduction
  • Wound healing (topical)
  • Detoxification
  • Antioxidant support
  • Skin health

Chlorophyll is the green pigment found in plants and algae, and supplements often use a stable form called chlorophyllin. It is most studied for reducing body and fecal odor and as a topical wound aid, but evidence for popular claims like detox and weight loss is weak. It is generally well tolerated for most adults, but talk with your pharmacist or doctor before starting, especially if you are pregnant or breastfeeding.

Read the full Chlorophyll 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 & Chlorophyll

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

0Major
336Moderate
0Minor
2,493No known interaction
336 Moderate 2,493 No interaction
Moderate

336 interactions

Showing 60 of 336 moderate interactions — see all 336 on the Chlorophyll page.

No interaction 2,493 drugs checked — show the list

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

Showing the 60 most looked-up of 2,493 medications checked with no known interaction — see the full Chlorophyll list.

See the full Chlorophyll 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
Chlorophyll 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 Chlorophyll and Fluorouracil Together: Common Questions

Can you take Chlorophyll 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 Chlorophyll 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 Chlorophyll?

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.