Drug & supplement interaction

Bitter Melon + Metformin

Metformin brand names: Glucophage, Metformin.

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

Bitter Melon has a moderate interaction with Metformin. Taking bitter melon with antidiabetes drugs might increase the risk of hypoglycemia.

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

Bitter Melon and Metformin

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin

Metformin falls under ANTIDIABETES DRUGS — the group Bitter Melon interacts with.

Taking bitter melon with antidiabetes drugs might increase the risk of hypoglycemia.
Bitter melon can lower blood glucose levels and might have additive effects when used with antidiabetes drugs. This might increase the risk of hypoglycemia in some patients. Monitor blood glucose levels closely.
Severity Moderate Likelihood Probable Evidence B

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: bitter melon has its own mild blood-sugar-lowering effect, and metformin is already working to bring your glucose down. Stack the two together and the effects can add up, which means your blood sugar could dip lower than you expect. That's where the caution comes in.

Watch for the usual signs of low blood sugar: shakiness, sweating, a racing heart, dizziness, irritability, or feeling foggy. Metformin on its own rarely causes lows, but pairing it with bitter melon raises the odds. The research behind this is real but modest, so don't panic. Just check your sugars more closely if you add bitter melon, and chat with your pharmacist or doctor before making any changes to your routine.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Leatherdale B, Panesar RK, Singh G, et al. Improvement in glucose tolerance due to Momordica charantia. Br Med J (Clin Res Ed) 1981;282:1823-4.
  2. Welihinda J, et al. Effect of Momordica charantia on the glucose tolerance in maturity onset diabetes. J Ethnopharmacol 1986;17:277-82. PubMed
  3. Srivastava Y, Venkatakrishna-Bhatt H, Verma Y, et al. Antidiabetic and adaptogenic properties of Momordica charantia extract: An experimental and clinical evaluation. Phytother Res 1993;7:285-9.
  4. Baldwa VS, Bhandari CM, Pangaria A, Goyal RK. Clinical trial in patients with diabetes mellitus of an insulin-like compound obtained from plant sources. Ups J Med Sci 1977;82:39-41. PubMed
  5. Aslam M, Stockley IH. Interaction between curry ingredient (karela) and drug (chlorpropamide). Lancet 1979:1:607. PubMed
  6. Ahmad N, Hassan MR, Halder H, Bennoor KS. Effect of Momordica charantia (Karolla) extracts on fasting and postprandial serum glucose levels in NIDDM patients (abstract). Bangladesh Med Res Counc Bull 1999;25:11-3.
  7. Yin RV, Lee NC, Hirpara H, Phung OJ. T. The effect of bitter melon (Mormordica charantia) in patients with diabetes mellitus: s systematic review and meta-analysis. Nutr Diabetes. 2014;4:e145.
  8. Rahman IU, Khan RU, Rahman KU, Bashir M. Lower hypoglycemic but higher antiatherogenic effects of bitter melon than glibenclamide in type 2 diabetic patients. Nutr J. 2015;14:13. PubMed
  9. Alam MA, Uddin R, Subhan N, Rahman MM, Jain P, Reza HM. Beneficial role of bitter melon supplementation in obesity and related complications in metabolic syndrome. J Lipids. 2015;2015:496169. PubMed
  10. Peter EL, Kasali FM, Deyno S, et al. Momordica charantia L. lowers elevated glycaemia in type 2 diabetes mellitus patients: Systematic review and meta-analysis. J Ethnopharmacol. 2019;231:311-24. doi: 10.1016/j.jep.2018.10.033. PubMed
  11. Chattopadhyay K, Wang H, Kaur J, et al. Effectiveness and Safety of Ayurvedic Medicines in Type 2 Diabetes Mellitus Management: A Systematic Review and Meta-Analysis. Front Pharmacol. 2022;13:821810. Published 2022 Jun 8. 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

Bitter Melon Also Interacts With Other Medications

Bitter Melon has 281 moderate known drug interactions in our database — the Metformin 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. Metformin)
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.

From our Q&A

Questions About Bitter Melon or Metformin

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

This page covers Bitter Melon only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin page lists 258 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate) and Agaricus Mushroom (moderate).

By severity: 2 major · 217 moderate · 39 minor.

From our pharmacist’s overview on the Metformin page

“Siberian cocklebur is the ingredient I most want anyone taking metformin (Glucophage) to know about. It has caused severe low blood sugar in people, documented in humans, and it should not be combined with any glucose-lowering medication.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin 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 Metformin 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 Metformin 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%

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

29 days ago today
Medication Metformin
Top 1%

#29 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 Metformin

What Is Metformin Used For?

Brand names: Glucophage, Metformin

Metformin is used to improve blood sugar (glucose) control in people with type 2 diabetes mellitus. It is always used together with diet and exercise, not instead of them.

Metformin hydrochloride tablets and oral solution are approved for adults and children 10 years and older. Metformin hydrochloride extended-release tablets — including brands such as Fortamet, Glumetza, and Metformin Hydrochloride Extended Release — are approved for adults only.

See full Metformin 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 Metformin, 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 Metformin supplement interactions › Every supplement checked against Metformin, ranked by severity Metformin 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 Metformin Together: Common Questions

Can you take Bitter Melon with Metformin?
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 Metformin 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 Metformin and Bitter Melon?

Our pharmacists answer your medication & supplement questions — free.

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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.