Medication interaction hub

What Supplements Interact with Irinotecan?

Irinotecan brand names: Camptosar, Onivyde. Every interaction below applies to the brands too.

153 Interactions 5 Major 107 Moderate 41 Minor
Curated & coded by · Clinical Pharmacist · Updated September 22, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Irinotecan? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Irinotecan against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

St. John's wort is the single riskiest supplement for anyone receiving irinotecan (Camptosar, Onivyde). Taken daily, it cut irinotecan blood levels by at least half and sped clearance of its active form, and for a chemotherapy medicine that can mean the cancer treatment quietly underperforms. Five of the 153 ingredients on file rate major, so this is a list to treat warily. Grapefruit is another of the five, pushing the opposite way by blocking the CYP3A4 enzyme so irinotecan levels and side effect risk rise.

Most of the remaining entries, 107 moderate and 41 minor, pull the same two levers. More than 120 ingredients touch CYP3A4, nudging irinotecan levels up or down, and 17 affect OATP transporters, which is how ordinary apple and orange juice earned major ratings here. Review everything you take with your oncology pharmacist, because during chemotherapy even small shifts in drug level carry real weight.

— , Clinical Pharmacist · July 18, 2026

Major 5 Moderate 107 Minor 41 No known interaction 1,299

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Most Viewed Ingredient Interactions

Irinotecan: Top Interactions at a Glance

The Irinotecan supplement & herbal interactions people checked most in the last 24 hours, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 153 interacting ingredients — plus 1,299 more checked with no known interaction. See the complete ranked list.

Start here

The Most-Checked Irinotecan Combinations Today

The Irinotecan + supplement pages people viewed most in the last 24 hours (resets at midnight). Open any card for the full report.

Major Likelihood Likely Apple + Irinotecani

Concomitant consumption of apple juice can significantly decrease oral absorption and blood levels of OATP substrates.

Read the full interaction Minor Likelihood Possible Black Cohosh + Irinotecani

Black cohosh may inhibit one form of OATP, OATP2B1, which could reduce the bioavailability and clinical effects of OATP2B1 substrates.

Read the full interaction Moderate Likelihood Possible Glucosamine + Irinotecani

Theoretically glucosamine may induce resistance to topoisomerase II inhibitors.

Read the full interaction Major Likelihood Likely Sweet Orange + Irinotecani

Consuming sweet orange juice can decrease oral absorption of OATP substrates.

Read the full interaction Moderate Likelihood Possible Horny Goat Weed + Irinotecani

Theoretically, horny goat weed might increase the effects and side effects of CYP3A4 substrates.

Read the full interaction Major Likelihood Likely Grapefruit + Irinotecani

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.

Read the full interaction
The complete list

Every Supplement Checked Against Irinotecan

All 1,452 ingredients in our database, ranked by severity — 153 with a Irinotecan interaction on file and 1,299 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Irinotecan?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Apple with Irinotecan?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Concomitant consumption of apple juice can significantly decrease oral absorption and blood levels of OATP substrates.

Full Apple + Irinotecan answer

Can you take Black Cohosh with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Black cohosh may inhibit one form of OATP, OATP2B1, which could reduce the bioavailability and clinical effects of OATP2B1 substrates.

Full Black Cohosh + Irinotecan answer

Can you take Glucosamine with Irinotecan?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically glucosamine may induce resistance to topoisomerase II inhibitors.

Full Glucosamine + Irinotecan answer

Can you take Sweet Orange with Irinotecan?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Consuming sweet orange juice can decrease oral absorption of OATP substrates.

Full Sweet Orange + Irinotecan answer

Can you take Horny Goat Weed with Irinotecan?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, horny goat weed might increase the effects and side effects of CYP3A4 substrates.

Full Horny Goat Weed + Irinotecan answer

Can you take Ashwagandha with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, ashwagandha might decrease the levels and clinical effects of CYP3A4 substrates.

Full Ashwagandha + Irinotecan answer

Can you take Atractylodes with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, atractylodes might increase the levels of CYP3A4 substrates.

Full Atractylodes + Irinotecan answer

Can you take Bael with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Bael and its constituents marmelosin and marmesinin inhibited cytochrome P450 3A4 (CYP3A4) activity in vitro.

Full Bael + Irinotecan answer

Can you take Baikal Skullcap with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, Baikal skullcap might alter the levels and clinical effects of OATP substrates.

Full Baikal Skullcap + Irinotecan answer

Can you take Black Psyllium with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.

Full Black Psyllium + Irinotecan answer

Can you take Blond Psyllium with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.

Full Blond Psyllium + Irinotecan answer

Can you take Carob with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, carob might also impair the absorption of oral drugs.

Full Carob + Irinotecan answer

Can you take Cascara Sagrada with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.

Full Cascara Sagrada + Irinotecan answer

Can you take Eleuthero with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, eleuthero might decrease levels of drugs metabolized by OATP.

Full Eleuthero + Irinotecan answer

Can you take Fucus Vesiculosus with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.

Full Fucus Vesiculosus + Irinotecan answer

Can you take Hemp with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, hemp might decrease the levels and clinical effects of CYP3A4 substrates.

Full Hemp + Irinotecan answer

Can you take Hibiscus Sabdariffa with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP3A4 substrates.

Full Hibiscus Sabdariffa + Irinotecan answer

Can you take Honey with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, honey might decrease levels of drugs metabolized by CYP3A4, but research is conflicting.

Full Honey + Irinotecan answer

Can you take Hops with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, hops extract might alter metabolism of CYP3A4 substrates; however, this effect may not be clinically significant.

Full Hops + Irinotecan answer

Can you take Karaya Gum with Irinotecan?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Co-administration of oral drugs with bulk forming laxatives such as karaya gum may decrease, increase, or have no effect on the absorption o...

Full Karaya Gum + Irinotecan answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. 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.
  • Possible. 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
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Irinotecan is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Irinotecan, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Irinotecan sits in 8 interaction categories. Open any one to see what the group means:

Cytochrome P450 3A4 (Cyp3A4) Substrates 121 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

121 of the supplement ingredients on this page reach Irinotecan through this category.

Oral Drugs 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Irinotecan through this category.

Organic Anion-Transporting Polypeptide Substrates (Oatp) 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Irinotecan through this category.

Glucuronidated Drugs 12 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

12 of the supplement ingredients on this page reach Irinotecan through this category.

Antineoplastics 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Irinotecan through this category.

Irinotecan (Camptosar) 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Irinotecan through this category.

Topoisomerase I Inhibitors 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Irinotecan through this category.

Topoisomerase Ii Inhibitors 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Irinotecan through this category.

About Irinotecan

Irinotecan is a prescription medication also sold under the brand names Camptosar, Onivyde. Because supplements and herbal products can change how medications work — or how strongly — every ingredient on this page has been checked against it in our interaction database.

Generic name: Irinotecan  ·  Brand names: Camptosar, Onivyde.

See the full Irinotecan Lipid Complex Injection drug information
Check a real product

Take a Supplement Product? Check the Whole Bottle Against Irinotecan

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Irinotecan.

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Pharmacist Counseling Corner

Irinotecan & Supplements: Common Questions

What supplements interact with Irinotecan?
More than you might expect — 153 in total, though they are far from equal: 5 are rated major, 107 moderate, and 41 minor. The ranked list on this page puts the ones that genuinely matter first, and every entry opens a full report on that exact pair. The highest-ranked right now: Apple, Grapefruit, St. John's Wort.
Which Irinotecan supplement interactions are the most serious?
The 5 major-rated combinations — led by Apple, Grapefruit, St. John's Wort, Sweet Orange and Activated Charcoal — deserve real caution: these are the ones generally best avoided, or used only with your prescriber watching. If you take any of them today, don't panic and don't stop anything abruptly — call your pharmacist first. Jump to the ranked list.
Can I take vitamins or supplements while on Irinotecan?
Usually yes — most people on Irinotecan can take most supplements. The catch is the exceptions, and they aren't always the exotic ones (St. John's Wort trips up more prescriptions than almost anything sold next to it). Look up each ingredient you actually take in the list above, and treat "no known interaction" as a green-ish light, not a guarantee. Try the label scanner or the interaction checker.
Do brands like Camptosar have the same supplement interactions as Irinotecan?
Yes — Camptosar, Onivyde all contain Irinotecan, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
What about Irinotecan and my other medications?
This page covers Irinotecan against supplements and herbal ingredients. Checking Irinotecan against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker, or read the full Irinotecan Lipid Complex Injection drug information.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of September 22, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.