Drug & supplement interaction

Turmeric + Gefitinib

Gefitinib brand name: Iressa.

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

Gefitinib falls into 2 drug categories that Turmeric can interact with; the most serious is rated moderate. Theoretically, turmeric might increase the risk of liver damage when taken with hepatotoxic drugs.

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

Turmeric and Gefitinib

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Turmeric interacts with whole categories of medication. Gefitinib falls into 2 of those categories, so it can interact with Turmeric in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

HEPATOTOXIC DRUGS

1 of 2

Why this applies to Gefitinib

Gefitinib falls under HEPATOTOXIC DRUGS — the group Turmeric interacts with.

Theoretically, turmeric might increase the risk of liver damage when taken with hepatotoxic drugs.
There is concern that turmeric might cause hepatotoxicity, especially when highly bioavailable formulations are used in high doses.
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 with gefitinib (Iressa): this isn't about turmeric changing how strong your medication is. It's about the liver. Gefitinib can sometimes stress or inflame the liver on its own, and there have been scattered reports of turmeric, especially concentrated, high-dose supplements, doing the same. Put them together and the worry is that the strain could add up.

To be clear, this is theoretical and based on anecdotal reports, not strong proof, and the spice you cook with is very unlikely to matter. The bigger concern is potent curcumin capsules. Watch for yellowing of your skin or eyes, dark urine, or unusual tiredness, and please check with your oncologist or pharmacist before adding a turmeric supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lombardi N, Crescioli G, Maggini V, et al. Acute liver injury following turmeric use in Tuscany: an analysis of the Italian Phytovigilance database and systematic review of case reports. Br J Clin Pharmacol. 2020. PubMed
  2. Sohal A, Alhankawi D, Sandhu S, Chintanaboina J. Turmeric-induced hepatotoxicity: Report of 2 cases. Int Med Case Rep J 2021;14:849-852. PubMed
  3. 109288 Halegoua-DeMarzio D, Navarro V, Ahmad J, et al. Liver injury associated with turmeric-A growing problem: Ten cases from the drug-induced liver injury network [DILIN]. Am J Med. 2022:S0002-9343(22)00740-9. PubMed
  4. Arzallus T, Izagirre A, Castiella A, Torrente S, Garmendia M, Zapata EM. Drug induced autoimmune hepatitis after turmeric intake. Gastroenterol Hepatol 2023. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Gefitinib also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Turmeric might increase or decrease levels of drugs metabolized by CYP3A4.
In vitro and animal research show that turmeric and its constituents curcumin and curcuminoids inhibit CYP3A4. Also, 8 case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking turmeric and cancer medications that are CYP3A4 substrates, including everolimus, ruxolitinib, ibrutinib, and palbociclib, and bortezomib. In another case report, a transplant patient presented with acute nephrotoxicity and elevated tacrolimus levels after consuming turmeric powder at a dose of 15 or more spoonfuls daily for ten days prior. It was thought that turmeric increased levels of tacrolimus due to CYP3A4 inhibition.
Conversely, other in vitro research suggests that turmeric induces CYP3A4 activity, leading to reduced levels of CYP3A4 substrates. An animal model suggests that induction of CYP3A4 occurs after daily curcumin use for 1 week. However, the induction of CYP3A4 by turmeric has not been reported in humans.
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 short version on combining turmeric with gefitinib (Iressa). Your body relies on a liver enzyme called CYP3A4 to break down gefitinib. The curcumin in turmeric can nudge that enzyme in either direction. Most of the signal we have points to turmeric slowing this enzyme, which could let gefitinib build up. That might mean more of its usual side effects, like diarrhea, a bumpy acne-like rash, dry skin, or liver enzyme changes.

That said, this is mostly lab and animal data, plus a handful of case reports with other cancer drugs, so it's a possible concern rather than a proven one. A sprinkle of turmeric on your food is unlikely to matter, but concentrated curcumin capsules are a different story. Please check with your oncology team before adding any supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Appiah-Opong, R., Commandeur, J. N., Vugt-Lussenburg, B., and Vermeulen, N. P. Inhibition of human recombinant cytochrome P450s by curcumin and curcumin decomposition products. Toxicology 6-3-2007;235(1-2):83-91. PubMed
  2. Hou, X. L., Takahashi, K., Kinoshita, N., Qiu, F., Tanaka, K., Komatsu, K., Takahashi, K., and Azuma, J. Possible inhibitory mechanism of Curcuma drugs on CYP3A4 in 1alpha,25 dihydroxyvitamin D3 treated Caco-2 cells. Int.J Pharm 6-7-2007;337(1-2):169-177.
  3. Valentine, S. P., Le Nedelec, M. J., Menzies, A. R., Scandlyn, M. J., Goodin, M. G., and Rosengren, R. J. Curcumin modulates drug metabolizing enzymes in the female Swiss Webster mouse. Life Sci. 4-11-2006;78(20):2391-2398. PubMed
  4. Nayeri A, Wu S, Adams E, et al. Acute Calcineurin Inhibitor Nephrotoxicity Secondary to Turmeric Intake: A Case Report. Transplant Proc. 2017;49(1):198-200. PubMed
  5. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. PubMed
  6. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed
  7. Dibaei M, Hosseini A, Lavasani H, Kiani-Dehkordi B, Rouini M. Assessment of metabolic interaction between curcumin and tramadol using the isolated perfused rat liver. Heliyon 2024;10(15):e35070. 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

Turmeric Also Interacts With Other Medications

Turmeric has 1,055 moderate, 77 minor known drug interactions in our database — the Gefitinib one above is among them. If you take anything else, check it against the full list below.

Moderate 1,055 Minor 77 No known interaction 1,698 (incl. Gefitinib)
Taking anything else?

Check Another of Your Medications Against Turmeric

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

From our Q&A

Questions About Turmeric or Gefitinib

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

This page covers Turmeric only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Gefitinib page lists 168 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 124 moderate · 38 minor.

Open the Gefitinib interaction page

One more smart check

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

We hold 1,368 real supplement products containing Turmeric, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Turmeric. Your product may carry other ingredients that interact with Gefitinib too, on top of Turmeric — 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 Turmeric and Gefitinib 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 Turmeric
Top 5%

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

29 days ago today
Medication Gefitinib
Steady interest

#2,719 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 Turmeric

What is Turmeric?

Turmeric
  • Joint pain and arthritis
  • Inflammation
  • Digestive upset
  • Antioxidant support
  • Skin conditions

Turmeric is a popular spice whose main active compounds, curcuminoids, are studied mostly for inflammation and joint pain. Some research is promising, but quality is mixed and curcumin is poorly absorbed on its own. For most people, dietary amounts are safe, but talk to your pharmacist or doctor before taking concentrated supplements, especially if you are pregnant, nursing, or have a medical condition.

Read the full Turmeric monograph & all interactions
Medication

About Gefitinib

What Is Gefitinib Used For?

Brand name: Iressa

Gefitinib tablets — sold under the brand name Iressa — are used as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). This treatment is only for patients whose tumors carry specific changes (mutations) in the EGFR gene: either an exon 19 deletion or an exon 21 (L858R) substitution mutation, confirmed by an FDA-approved test.

This medicine is not established as safe or effective for NSCLC patients with other types of EGFR mutations. Your doctor will use a genetic test on your tumor or blood to confirm whether gefitinib is right for you.

See full Gefitinib drug information
Keep checking

Other Drugs & Turmeric

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

0Major
1,055Moderate
77Minor
1,697No known interaction
1,055 Moderate 77 Minor 1,697 No interaction
Moderate

1,055 interactions

Showing 60 of 1,055 moderate interactions — see all 1,055 on the Turmeric page.

Minor

77 interactions

Showing 60 of 77 minor interactions — see all 77 on the Turmeric page.

No interaction 1,697 drugs checked — show the list

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

Showing the 60 most looked-up of 1,697 medications checked with no known interaction — see the full Turmeric list.

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

Can you take Turmeric with Gefitinib?
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 Turmeric and Gefitinib?
Gefitinib belongs to more than one drug category, and Turmeric 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 Turmeric and Gefitinib 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 Gefitinib and Turmeric?

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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.