Drug & supplement interaction

Syrian Rue + Docetaxel

Docetaxel brand name: Taxotere.

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

Syrian Rue has a moderate interaction with Docetaxel. Theoretically, Syrian rue might increase the levels and clinical effects of drugs metabolized by CYP3A4.

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

Syrian Rue and Docetaxel

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Docetaxel

Docetaxel falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Syrian Rue interacts with.

Theoretically, Syrian rue might increase the levels and clinical effects of drugs metabolized by CYP3A4.
Syrian rue contains beta-carboline alkaloids, including harmine, harmol, and harmane. In vitro research suggests that these beta-carboline alkaloids competitively inhibit CYP3A4 enzymes.
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 for Docetaxel (Taxotere). Your body clears this chemo drug largely through a liver enzyme called CYP3A4. Lab studies suggest the harmala alkaloids in Syrian Rue can block that same enzyme. If clearance slows down, more docetaxel could linger in your system, which may mean stronger effects and a higher chance of side effects like low blood counts (raising infection risk), mouth sores, fatigue, nerve tingling, and fluid retention.

I want to be honest about how shaky this evidence is. It's theoretical, based on test-tube work, not real patient cases. Still, docetaxel is potent chemo where dosing is carefully calculated, so please don't combine these without first checking with your oncology team or pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Zhao, T., He, Y. Q., Wang, J., Ding, K. M., Wang, C. H., and Wang, Z. T. Inhibition of human cytochrome P450 enzymes 3A4 and 2D6 by β-carboline alkaloids, harmine derivatives. Phytother Res 2011;25(11):1671-1677.

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

Syrian Rue Also Interacts With Other Medications

Syrian Rue has 1,121 moderate known drug interactions in our database — the Docetaxel one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,121 No known interaction 1,709 (incl. Docetaxel)
Taking anything else?

Check Another of Your Medications Against Syrian Rue

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

Everything else you take

See Every Supplement That Interacts With Docetaxel

This page covers Syrian Rue only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Docetaxel page lists 121 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 2 major · 87 moderate · 32 minor.

From our pharmacist’s overview on the Docetaxel page

“Grapefruit is the first thing I would take off the menu during docetaxel (Taxotere) chemotherapy. It blocks CYP3A4, the liver enzyme that clears docetaxel, and higher levels of a chemotherapy drug mean harsher side effects, not better results.”

Reviewed by 2 · Jul 18, 2026

Open the Docetaxel interaction page

How much people look this up

Where Syrian Rue and Docetaxel 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 Syrian Rue
Steady interest

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

29 days ago today
Medication Docetaxel
Top half

#801 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 Syrian Rue

What is Syrian Rue?

  • Traditional remedy for digestive complaints
  • Used as a sedative or for mood
  • Antimicrobial and antiparasitic folk use
  • Used as a dye and incense
  • Recreational psychoactive use

Syrian Rue (Peganum harmala) is a traditional plant whose seeds contain potent compounds called harmala alkaloids, including MAO-inhibiting harmine and harmaline. There is little reliable human evidence that it safely treats any condition, and it carries real risks of toxicity, so it is not recommended for self-treatment. Talk to a pharmacist or doctor before considering it.

Read the full Syrian Rue monograph & all interactions
Medication

About Docetaxel Injection

What Is Docetaxel Injection Used For?

Brand name: Taxotere

Docetaxel Injection is used to treat a number of serious cancers. Beizray (docetaxel injection) is approved as a single agent for locally advanced or metastatic breast cancer after prior chemotherapy has stopped working, and in combination with doxorubicin and cyclophosphamide as adjuvant (after-surgery) treatment for operable node-positive breast cancer. It is also used as a single agent for locally advanced or metastatic non-small cell lung cancer (NSCLC) after platinum-based chemotherapy has failed, and with cisplatin for chemotherapy-naive advanced NSCLC.

Beizray is used with prednisone for metastatic castration-resistant prostate cancer. It is also used with cisplatin and fluorouracil for advanced gastric adenocarcinoma (including gastroesophageal junction cancer) in patients who have not received prior chemotherapy for advanced disease, and for induction treatment of locally advanced squamous cell carcinoma of the head and neck (SCCHN).

See full Docetaxel Injection drug information
Keep checking

Other Drugs & Syrian Rue

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

0Major
1,121Moderate
0Minor
1,708No known interaction
1,121 Moderate 1,708 No interaction
Moderate

1,121 interactions

Showing 60 of 1,121 moderate interactions — see all 1,121 on the Syrian Rue page.

No interaction 1,708 drugs checked — show the list

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

Showing the 60 most looked-up of 1,708 medications checked with no known interaction — see the full Syrian Rue list.

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

Can you take Syrian Rue with Docetaxel?
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 Syrian Rue and Docetaxel 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 Docetaxel and Syrian Rue?

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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.