Bitter Melon (Momordica charantia): Uses, Evidence and Safety

Bitter melon can lower blood sugar, so tell your pharmacist if you take diabetes medicine. The trials below measured blood sugar falling, and the sources we read did not settle how bitter melon combines with diabetes medicines. A rat study of the water extract of the unripe fruit found birth defects, and its authors advised caution in people, but we found no human pregnancy data (see Safety). [1]

What bitter melon is

Bitter melon, also called bitter gourd, is Momordica charantia L., family Cucurbitaceae. [2] It is a vegetable and, in traditional medicine, a remedy. A Cochrane review describes it as a nutritious vegetable also used in traditional medical practices to treat type 2 diabetes. [3] The NCCIH address we tried for it returned "not found", we did not find an EMA monograph page, and MedlinePlus says its herb and supplement database from the Therapeutic Research Center became unavailable on July 29, 2025. [4] That is why this page relies on reviews of trials.

Traditional use

This is tradition, not proof. The sources we read say only that bitter melon is used in traditional medical practices to treat type 2 diabetes. [3] They do not name peoples, regions or periods, so we do not.

What research shows

All human findings below are about type 2 diabetes. Animal findings are kept separate.

Because Cochrane found that no similar preparation was tested twice, results for one capsule, powder or juice cannot be assumed for another. [3]

Forms

Trials have used capsules and tablets in the studies reviewed. [6] Eating bitter melon as a vegetable is a different exposure from a supplement, and we do not describe how to prepare it or give amounts.

Safety

• Pregnancy and breastfeeding: the only pregnancy finding we read is the rat study, which advised caution in people. [1] Human safety: Proper evidence not found in the sources we read. Searched: PubMed (bitter melon with pregnancy, safety, toxicity, favism), NCCIH, EMA, MedlinePlus; LactMed and LiverTox were not readable. See Pregnancy and Breastfeeding.
• Blood sugar medicines: the reviews found lower blood sugar, and the Cochrane review included trials that compared bitter melon with metformin or glibenclamide. [5][3] Specific low-blood-sugar reports with medicine combinations were not found in the sources we read. Read Supplements and Diabetes Medicines and How Interactions Work, and ask the prescriber or pharmacist. Never stop or change a diabetes medicine on your own.
• Side effects in trials: no serious adverse events related to supplementation were reported in the 2024 meta-analysis, and the common events were digestive complaints such as diarrhea, gas, nausea and constipation. [6] The Cochrane review also reports no serious adverse effects but notes that adverse-effect reporting was incomplete. [3][7]
• Favism (G6PD deficiency), seeds, children, liver, kidney, bleeding, surgery: not described in the sources we read, so we make no claim either way. Lack of information is not proof of safety. Tell the surgical team about any supplement: Supplements Before Surgery.

Quality

Cochrane's authors called for work on standardization and quality control of preparations, since products differed. [3] See Quality Testing and Certifications. For other herbs studied for blood sugar, see Herbs for Blood Sugar and Diabetes.

We give no amounts. A clinician or pharmacist decides what suits a person.