Drug & supplement interaction

Bitter Melon + Vincristine

Vincristine brand name: Vincasar.

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

Bitter Melon has a moderate interaction with Vincristine. Theoretically, bitter melon might increase levels of P-glycoprotein substrates.

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

Bitter Melon and Vincristine

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

Moderate

P-GLYCOPROTEIN SUBSTRATES

Why this applies to Vincristine

Vincristine falls under P-GLYCOPROTEIN SUBSTRATES — the group Bitter Melon interacts with.

Theoretically, bitter melon might increase levels of P-glycoprotein substrates.
Bitter melon might inhibit the p-glycoprotein (P-gp) intestinal pump and increase intracellular levels of P-gp substrates. In vitro research in intestinal cells shows that 1-monopalmitin, a constituent of bitter melon, increases levels of daunomycin, a P-gp substrate. Additionally, drinking bitter melon juice has been associated with a case of acute pancreatitis in a patient who had been taking pazopanib, a P-gp substrate, for 8 years. Researchers theorize that inhibition of P-gp led to increased levels of pazopanib, resulting in pazopanib-induced pancreatitis.
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. Vincristine is pushed out of your cells by a little pump called P-glycoprotein, which helps keep its levels in check. Bitter melon may slow that pump down, at least in lab studies. If that happened in a real person, more vincristine could hang around inside cells, which could mean a stronger dose effect than intended.

Why that matters here: vincristine's tough side effects include nerve problems (tingling, numbness, weakness, constipation) and low blood counts. More drug in the body could make those worse. That said, this is theoretical, based mostly on test-tube and animal data, not solid human proof. Still, since you're on chemo, please run any bitter melon (juice or supplements) past your oncology team first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Konishi T, Satsu H, Hatsugai Y, et al. Inhibitory effect of a bitter melon extract on the P-glycoprotein activity in intestinal Caco-2 cells. Br J Pharmacol. 2004;143(3):379-87. PubMed
  2. Unsal O, Sütcüoglu O, Yazici O. Dangerous interaction of bitter melon (Momordica charantia) with pazopanib: a case of acute pancreatitis. J Oncol Pharm Pract 2022;28(2):486-8.

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

Bitter Melon Also Interacts With Other Medications

Bitter Melon has 281 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 281 No known interaction 2,549 (incl. Vincristine)
Taking anything else?

Check Another of Your Medications Against Bitter Melon

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

Everything else you take

See Every Supplement That Interacts With Vincristine

This page covers Bitter Melon 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 Bitter Melon as Part of a Dietary Supplement Product? Check It for Interactions

We hold 736 real supplement products containing Bitter Melon, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bitter Melon. Your product may carry other ingredients that interact with Vincristine too, on top of Bitter Melon — 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 Bitter Melon 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 Bitter Melon
Top 25%

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

29 days ago today
Medication Vincristine
Steady interest

#2,594 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 Bitter Melon

What is Bitter Melon?

Bitter Melon
  • Blood sugar support
  • Diabetes
  • Digestive complaints
  • Antioxidant source
  • Skin conditions

Bitter melon is a tropical fruit eaten as food and used in traditional medicine, most often for blood sugar control. While some small studies hint it may modestly lower blood sugar, the evidence is limited and inconsistent, so it should not replace proven diabetes treatment. Talk with your pharmacist or doctor before using it, especially if you take diabetes medicines or are pregnant.

Read the full Bitter Melon 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 & Bitter Melon

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

0Major
281Moderate
0Minor
2,548No known interaction
281 Moderate 2,548 No interaction
Moderate

281 interactions

Showing 60 of 281 moderate interactions — see all 281 on the Bitter Melon page.

No interaction 2,548 drugs checked — show the list

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

Showing the 60 most looked-up of 2,548 medications checked with no known interaction — see the full Bitter Melon list.

See the full Bitter Melon 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
Bitter Melon 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 Bitter Melon and Vincristine Together: Common Questions

Can you take Bitter Melon 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 Bitter Melon 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 Bitter Melon?

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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.