Drug & supplement interaction

Peony + Vincristine

Vincristine brand name: Vincasar.

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

Peony has a moderate interaction with Vincristine. Theoretically, use of peony may 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

Peony and Vincristine

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Vincristine

Vincristine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Peony interacts with.

Theoretically, use of peony may increase the levels and clinical effects of drugs metabolized by CYP3A4.
In vitro research shows that peony suppresses the metabolism of clozapine via weak-to-moderate inhibitory effects on CYP1A2 and CYP3A4. This effect 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 idea behind this one. Your body relies on a liver enzyme called CYP3A4 to break down vincristine and clear it out. Lab and animal studies hint that peony root may gently slow that same enzyme. If it did, vincristine could linger in your system a little longer and hit harder. With this chemo drug, that matters because its main side effects are nerve-related, things like tingling, numbness, weakness, constipation, and belly pain, plus drops in your blood counts.

I want to be honest, though: this is theoretical and based only on test-tube work with a different drug, never shown in actual people. Even so, vincristine is serious medicine, so please don't add peony without first clearing it with your oncology team or pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wang W, Tian DD, Zheng B, et al. Peony-glycyrrhiza decoction, an herbal preparation, inhibits clozapine metabolism via cytochrome P450s, but not flavin-containing monooxygenase in in vitro models. Drug Metab Dispos 2015;43(7):1147-53. 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

Peony Also Interacts With Other Medications

Peony has 810 moderate known drug interactions in our database — the Vincristine one above is one of them. If you take anything else, check it against the full list below.

Moderate 810 No known interaction 2,020 (incl. Vincristine)
Taking anything else?

Check Another of Your Medications Against Peony

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

Everything else you take

See Every Supplement That Interacts With Vincristine

This page covers Peony only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Vincristine page lists 148 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 3 major · 108 moderate · 37 minor.

From our pharmacist’s overview on the Vincristine page

“Because vincristine (Vincasar) is chemotherapy, used against leukemias, lymphomas, and several other cancers, the interactions on this page deserve genuine caution, starting with the three rated major. Nearly all of these supplements change how the body clears vincristine, through the CYP3A4 enzyme or the P-glycoprotein transporter, wh…”

Reviewed by 2 · Jul 18, 2026

Open the Vincristine interaction page

One more smart check

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

We hold 71 real supplement products containing Peony, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Peony. Your product may carry other ingredients that interact with Vincristine too, on top of Peony — 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 Peony and Vincristine 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 Peony
Top 25%

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

29 days ago today
Medication Vincristine
Steady interest

#2,313 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 Peony

What is Peony?

Peony
  • Menstrual cramps and irregular periods
  • Muscle cramps and spasms
  • Anxiety and stress
  • Inflammation and pain
  • Polycystic ovary syndrome (PCOS)

Peony root is a traditional Chinese medicine herb often used for menstrual problems, cramps, and inflammation, frequently as part of combination formulas. Human evidence for most uses is limited or preliminary, so it should not replace proven treatments. Talk to your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or taking other medicines.

Read the full Peony monograph & all interactions
Medication

About Vincristine Injection

What Is Vincristine Injection Used For?

Brand name: Vincasar

Vincristine Sulfate Injection is approved to treat acute leukemia. It is also used as part of combination chemotherapy regimens for Hodgkin's disease, non-Hodgkin's malignant lymphomas, rhabdomyosarcoma (a soft-tissue cancer), neuroblastoma (a cancer of nerve tissue), and Wilms' tumor (a kidney cancer in children).

Because it works best alongside other cancer medicines, vincristine is almost always given as part of a multi-drug treatment plan rather than on its own.

See full Vincristine Injection drug information
Keep checking

Other Drugs & Peony

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

0Major
810Moderate
0Minor
2,019No known interaction
810 Moderate 2,019 No interaction
Moderate

810 interactions

Showing 60 of 810 moderate interactions — see all 810 on the Peony page.

No interaction 2,019 drugs checked — show the list

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

Showing the 60 most looked-up of 2,019 medications checked with no known interaction — see the full Peony list.

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

Can you take Peony with Vincristine?
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 Peony and Vincristine 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 Vincristine and Peony?

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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.