Drug & supplement interaction

Cassia Cinnamon + Lurbinectedin

Lurbinectedin brand name: Zepzelca.

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

Cassia Cinnamon has a moderate interaction with Lurbinectedin. Theoretically, large doses of cassia cinnamon might cause additive effects when used with hepatotoxic drugs.

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

Cassia Cinnamon and Lurbinectedin

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Lurbinectedin

Lurbinectedin falls under HEPATOTOXIC DRUGS — the group Cassia Cinnamon interacts with.

Theoretically, large doses of cassia cinnamon might cause additive effects when used with hepatotoxic drugs.
There is some concern that ingesting large amounts of cassia cinnamon for an extended duration might cause hepatotoxicity in some people. Cassia cinnamon contains coumarin, which can cause hepatotoxicity in animal models. In humans, very high doses of coumarin from 50-7000 mg/day can result in hepatotoxicity that resolves when coumarin use is discontinued. Lower amounts might also cause liver problems in sensitive people, such as those with liver disease or those taking potentially hepatotoxic agents.
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 thing to know about Zepzelca (lurbinectedin): it's a chemotherapy drug that can be tough on your liver on its own. Doctors actually watch your liver enzymes during treatment for that reason. Cassia cinnamon, the cheap everyday kind, naturally contains a compound called coumarin, and in large supplement-sized doses taken over time, that coumarin has been linked to liver stress in sensitive people.

So the worry here is simple: stacking two things that can each burden the liver might add up. To be honest, this is a theoretical concern based on how each works, not something proven in studies, so I don't want to scare you. Sprinkling cinnamon on your oatmeal is not the issue, high-dose capsules are. Please run any cinnamon supplement past your oncologist or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Press release. Cinnamon capsules to reduce blood sugar are medicinal products! Efficacy has not been scientifically proven - some products contain high levels of coumarin. Federal Institute of Risk Assessment (BfM), Germany, November 11, 2006. Available a
  2. Felter SP, Vassallo JD, Carlton BD, Daston GP. A safety assessment of coumarin taking into account species-specificity of toxicokinetics. Food Chem Toxicol 2006;44:462-75. PubMed
  3. Choi, J., Lee, K. T., Ka, H., Jung, W. T., Jung, H. J., and Park, H. J. Constituents of the essential oil of the Cinnamomum cassia stem bark and the biological properties. Arch Pharm Res 2001;24(5):418-423.
  4. Brancheau D, Patel B, Zughaib M. Do cinnamon supplements cause acute hepatitis? Am J Case Rep 2015;16:250-4. 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

Cassia Cinnamon Also Interacts With Other Medications

Cassia Cinnamon has 441 moderate known drug interactions in our database — the Lurbinectedin one above is one of them. If you take anything else, check it against the full list below.

Moderate 441 No known interaction 2,389 (incl. Lurbinectedin)
Taking anything else?

Check Another of Your Medications Against Cassia Cinnamon

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

Everything else you take

See Every Supplement That Interacts With Lurbinectedin

This page covers Cassia Cinnamon only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lurbinectedin page lists 156 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 5 major · 122 moderate · 29 minor.

From our pharmacist’s overview on the Lurbinectedin page

“Lurbinectedin (Zepzelca) is chemotherapy for small cell lung cancer, and with a drug this potent the 156 supplement interactions on file warrant real attention. Five carry a major rating, and those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Lurbinectedin interaction page

One more smart check

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

We hold 3,249 real supplement products containing Cassia Cinnamon, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cassia Cinnamon. Your product may carry other ingredients that interact with Lurbinectedin too, on top of Cassia Cinnamon — 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 Cassia Cinnamon and Lurbinectedin 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 Cassia Cinnamon
Top 10%

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

29 days ago today
Medication Lurbinectedin
Steady interest

#2,643 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 Cassia Cinnamon

What is Cassia Cinnamon?

Cassia Cinnamon
  • Blood sugar support
  • Digestive upset
  • Antioxidant support
  • Flavoring and culinary use
  • Antimicrobial

Cassia cinnamon is the common, inexpensive cinnamon used in cooking, and it is also taken as a supplement, most often for blood sugar support. The evidence for its health benefits is mixed and far from proven, and because cassia is naturally high in coumarin, taking large amounts regularly may stress the liver. Use food amounts freely, but talk with a pharmacist or doctor before using high-dose supplements.

Read the full Cassia Cinnamon monograph & all interactions
Medication

About Lurbinectedin Injection

What Is Lurbinectedin Injection Used For?

Brand name: Zepzelca

Zepzelca (lurbinectedin) injection is approved for adults with small cell lung cancer (SCLC) in two settings. First, Zepzelca is used in combination with atezolizumab (or atezolizumab and hyaluronidase-tqjs) as maintenance treatment for extensive-stage small cell lung cancer (ES-SCLC) in patients whose disease did not progress after initial treatment with those same immunotherapy drugs plus carboplatin and etoposide.

Second, Zepzelca is approved as a single agent for adults with metastatic small cell lung cancer whose cancer has worsened during or after platinum-based chemotherapy. This second use was granted accelerated approval based on tumor response rates, and continued approval depends on results from confirmatory clinical trials.

See full Lurbinectedin Injection drug information
Keep checking

Other Drugs & Cassia Cinnamon

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

0Major
441Moderate
0Minor
2,388No known interaction
441 Moderate 2,388 No interaction
Moderate

441 interactions

Showing 60 of 441 moderate interactions — see all 441 on the Cassia Cinnamon page.

No interaction 2,388 drugs checked — show the list

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

Showing the 60 most looked-up of 2,388 medications checked with no known interaction — see the full Cassia Cinnamon list.

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

Can you take Cassia Cinnamon with Lurbinectedin?
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 Cassia Cinnamon and Lurbinectedin 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 Lurbinectedin and Cassia Cinnamon?

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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.