Drug & supplement interaction

Bitter Melon + Tadalafil

Tadalafil brand names: Cialis, Tadliq.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Bitter Melon and Tadalafil in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Bitter Melon and Tadalafil

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Tadalafil and Bitter Melon in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Bitter Melon safety at a glance

Bitter Melon overall Use caution Generally tolerated as food, but supplement amounts may lower blood sugar and cause stomach upset.
Pregnancy Avoid Traditionally avoided in pregnancy because seeds and high doses may cause uterine or other harmful effects.
Breastfeeding Use caution Not enough reliable safety information, so it is best avoided while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Tadalafil and Bitter Melon? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Tadalafil

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tadalafil is filed under 5 classifications — including phosphodiesterase-5 inhibitors, vasodilators, cytochrome p450 3a4 (cyp3a4) substrates. Bitter Melon has documented interactions with 3 drug classes — the most serious being antidiabetes drugs (moderate), p-glycoprotein substrates (moderate) and pazopanib (votrient) (moderate) — and none of Tadalafil’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Bitter Melon Does Interact With Other Medications

Bitter Melon has 282 moderate known drug interactions in our database — Tadalafil isn’t one of them. If you take anything else, check it against the full list below.

Moderate 282 No known interaction 2,548 (incl. Tadalafil)
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.

What to actually watch for

No Interaction Found — But Data Suggests Bitter Melon and Tadalafil May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Stomach upset Additional detail

    Bitter Melon

    “The most common adverse effects associated with bitter melon in clinical studies are gastrointestinal, such as heartburn, anorexia, nausea, vomiting, diarrhea, constipation, flatulence, and abdominal discomfort. In one study, these events occurred in about 3% to 16% of patients taking bitter melon.”

    Bitter Melon · Natural Medicines adverse-effect record, reported in anorexia.

    4 sources cited
    1. 92126. 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
    2. 100632. 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
    3. 100633. Cortez-Navarrete M, Martínez-Abundis E, Pérez-Rubio KG, González-Ortiz M, Méndez-Del Villar M. Momordica charantia administration improves insulin secretion in type 2 diabetes mellitus. J Med Food. 2018;21(7):672-7. doi: 10.108
    4. 106408. Kim SK, Jung J, Jung JH, et al. Hypoglycemic efficacy and safety of Momordica charantia (bitter melon) in patients with type 2 diabetes mellitus. Complement Ther Med. 2020 Aug;52:102524. doi: 10.1016/j.ctim.2020.102524. PubMed

    Tadalafil

    Listed in the ADVERSE REACTIONS section of the FDA label for Tadalafil. Read the label on DailyMed ›

  • Headache reported in 11.1% of FDA reports for Tadalafil Additional detail

    Bitter Melon

    “Headaches, dizziness, and fatigue have been reported after the ingestion of bitter melon. In one clinical study, about 5% of patients taking bitter melon 2-4 grams daily reported dizziness. Two cases of seizures have occurred in children after administration of a bitter melon tea.”

    Bitter Melon · Natural Medicines adverse-effect record, reported in epilepsy.

    4 sources cited
    1. 15568. Basch E, Gabardi S, Ulbricht C. Bitter melon (Momordica charantia): a review of efficacy and safety. Am J Health Syst Pharm 2003;60:356-9. PubMed
    2. 92126. 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
    3. 100633. Cortez-Navarrete M, Martínez-Abundis E, Pérez-Rubio KG, González-Ortiz M, Méndez-Del Villar M. Momordica charantia administration improves insulin secretion in type 2 diabetes mellitus. J Med Food. 2018;21(7):672-7. doi: 10.108
    4. 112372. Kim B, Lee HS, Kim HJ, et al. Momordica charantia (bitter melon) efficacy and safety on glucose metabolism in Korean prediabetes participants: a 12-week, randomized clinical study. Food Sci Biotechnol 2022;32(5):697-704. PubMed

    Tadalafil

    Listed in the ADVERSE REACTIONS section of the FDA label for Tadalafil, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Bitter Melon but not commonly for Tadalafil: constipation, bloating or gas, heartburn and dizziness.

Effects for Tadalafil come from the ADVERSE REACTIONS section of its FDA label; effects for Bitter Melon come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 98,103 voluntary FDA FAERS reports for Tadalafil that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Bitter Melon or Tadalafil

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 Tadalafil, 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 Tadalafil

This page covers Bitter Melon only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tadalafil page lists 144 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Mistletoe (major), Grapefruit (major), Hawthorn (major) and St. John's Wort (major).

By severity: 5 major · 98 moderate · 41 minor.

From our pharmacist’s overview on the Tadalafil page

“Grapefruit juice is the first thing to know about if you take tadalafil (Cialis, Tadliq). It blocks CYP3A4, the enzyme that clears the drug, so blood levels climb and side effects like a steep drop in blood pressure become more likely.”

Reviewed by 2 · Jul 18, 2026

Open the Tadalafil 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. Even though Bitter Melon itself has no known interaction with Tadalafil, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Bitter Melon and Tadalafil 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%

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

29 days ago today
Medication Tadalafil
Top 1%

#16 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Bitter Melon reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Bitter Melon and Tadalafil records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Momordica charantia · Cucurbitaceae · Fruit, seeds, leaves, and juice · Fresh fruit, juice, capsules, dried powder, tea, extracts

An interaction check asks whether these two react with each other — it does not ask whether Bitter Melon is a good idea for someone in your situation. Here is what our Bitter Melon record says about it on its own.

Bitter Melon: dosing

There is no well-established standard dose for bitter melon. Studies have used different forms, including fresh fruit, juice, and extracts, which makes it hard to give a single reliable amount.If you choose to use a supplement, follow the directions on the product label and do not exceed the recommended amount.

From our Bitter Melon monograph — the full record covers uses, side effects and every documented interaction.

Read the full Bitter Melon monograph & all interactions
Medication

About Tadalafil

What Is Tadalafil Used For?

Brand names: Cialis, Tadliq

Tadalafil tablets (including Cialis and generic tadalafil) are used to treat erectile dysfunction (ED), the symptoms of benign prostatic hyperplasia (BPH — an enlarged prostate), or both conditions together. When used with the drug finasteride to start BPH treatment, this combination is recommended for up to 26 weeks.

Adcirca, Alyq (tablets), and Tadliq (oral suspension) are indicated specifically for pulmonary arterial hypertension (PAH — high blood pressure in the lungs), to improve the ability to exercise.

Most-Reported Side Effects for Tadalafil

From FAERS, the FDA’s public side-effect reporting system (99,210 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 11,917 reports
Headache 10,982 reports
Diarrhea 8,020 reports
Nausea 6,697 reports
Fatigue 6,080 reports
See full Tadalafil 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
282Moderate
0Minor
2,547No known interaction
282 Moderate 2,547 No interaction
Moderate

282 interactions

Showing 60 of 282 moderate interactions — see all 282 on the Bitter Melon page.

No interaction 2,547 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 2,547 medications checked with no known interaction — see the full Bitter Melon list.

See the full Bitter Melon interactions page
See every supplement checked against Tadalafil, ranked by severity
Evidence & sources

Bitter Melon References

The 18 references that drive our Bitter Melon monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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. Basch E, Gabardi S, Ulbricht C. Bitter melon (Momordica charantia): a review of efficacy and safety. Am J Health Syst Pharm 2003;60:356-9. PubMed
  8. 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.
  9. 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
  10. 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
  11. 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
  12. 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
  13. Cortez-Navarrete M, Martínez-Abundis E, Pérez-Rubio KG, González-Ortiz M, Méndez-Del Villar M. Momordica charantia administration improves insulin secretion in type 2 diabetes mellitus. J Med Food. 2018;21(7):672-7. doi: 10.108
  14. Kim SK, Jung J, Jung JH, et al. Hypoglycemic efficacy and safety of Momordica charantia (bitter melon) in patients with type 2 diabetes mellitus. Complement Ther Med. 2020 Aug;52:102524. doi: 10.1016/j.ctim.2020.102524. PubMed
  15. 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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Bitter Melon and Tadalafil Together: Common Questions

Is it safe to take Bitter Melon with Tadalafil?
We do not list a known interaction between Bitter Melon and Tadalafil. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Bitter Melon and Tadalafil have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Bitter Melon and Tadalafil combination checked?
Interactions in our licensed database are recorded against drug classes. Tadalafil is filed under 5 classifications, and Bitter Melon has documented interactions with 3 drug classes — none of Tadalafil's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Bitter Melon interact with any other medications?
Yes. Bitter Melon has 282 documented drug interactions in our database — Tadalafil is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Tadalafil interact with any supplements?
Yes. Tadalafil has documented interactions with 144 supplements in our database — Bitter Melon is not one of them. The Tadalafil interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Bitter Melon monograph Uses, safety profile, and every drug interaction in one place Tadalafil drug information The full plain-English guide to this medication Tadalafil supplement interactions Every supplement checked against Tadalafil, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 18 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tadalafil 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.