Widely sold in Asian groceries as food, bitter melon is also a folk remedy for diabetes, cancer, and various infections.
Bitter melon continues to be advertised as an effective treatment for diabetes, especially of the type 2 (“adult-onset”) variety. However, evidence used to support this claim is limited to animal studies, uncontrolled human trials and other unreliable forms of evidence.1-6 Only double-blind, placebo-controlled studies can prove a treatment effective, and the single such study of bitter melon failed to find benefit.12 (For information on why double-blind studies are essential, see Why Does This Database Rely on Double-blind Studies?)
In test tube studies, a protein in bitter melon called MAP-30 kills viruses and slows the growth of some cancer cells. However, it is a long way from the test tube to real people, and there have not as yet been any human trials of bitter melon or its constituents for the treatment of cancer or viral diseases.
The typical dosage of bitter melon is one small, unripe, raw melon or about 50 to 100 ml of fresh juice, divided into 2 or 3 doses over the course of the day. The only problem is that bitter melon tastes extremely bitter. Noted naturopath Michael Murray suggests that you should "simply plug your nose and take a 2-ounce shot."7
As a widely eaten food in Asia, bitter melon is often regarded as safe. However, it does appear to present some health risks. The most significant of these comes from the fact that it may work! Combining bitter melon with standard drugs may reduce blood sugar too well, possibly leading to dangerously low blood sugar levels.8,9 In fact, there are case reports of two children with diabetes who went into hypoglycemic coma after taking bitter melon.10 For this reason, if you already take drugs for diabetes, you should add bitter melon to your diet only with a physician's supervision. (And definitely don't stop your medication and substitute bitter melon instead. It is not as powerful as insulin or other conventional treatments.)
Other possible risks include impaired fertility, liver inflammation, and spontaneous abortion.11
Safety in young children, nursing women, or those with severe kidney disease has not been established.
1. 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;7:285-289.
2. Welihinda J, Arvidson G, Gylfe E, et al. The insulin-releasing activity of the tropical plant Momordica charantia. Acta Biol Med Ger. 1982;41:1229-1240.
3. Welhinda J, Karunanayake EH, Sheriff MH, et al. Effect of Momordica charantia on the glucose tolerance in maturity onset diabetes. J Ethnopharmacol. 1986;17:277-282.
4. Leatherdale BA, Panesar RK, Singh G, et al. Improvement in glucose tolerance due to Momordica charantia (karela). Br Med J (Clin Res Ed). 1981;282:1823-1824.
5. Ahmad N, Hassan MR, Halder H, et al. Effect of Momordica charantia (Karolla) extracts on fasting and postprandial serum glucose levels in NIDDM patients. Bangladesh Med Res Counc Bull. 1999;25:11-13.
6. Jayasooriya AP, Sakono M, Yukizaki C, et al. Effects of momordica charantia powder on serum glucose levels and various lipid parameters in rats fed with cholesterol-free and cholesterol-enriched diets. J Ethnopharmacol. 2000;72:331-336.
7. Murray MT. The Healing Power of Herbs: The Enlightended Person's Guide to the Wonders of Medicinal Plants. 2nd ed. Rocklin, CA Prima Publishing; 1995:358.
8. Leatherdale BA, Panesar RK, Singh G, et al. Improvement in glucose tolerance due to Momordica charantia (karela). Br Med J (Clin Res Ed). 1981;282:1823-1824.
9. Aslam M, Stockley IH. Interaction between curry ingredient (karela) and drug (chlorpropamide). Lancet. 1979;1:607.
10. Hulin A, Wavelet M, Desbordes JM. Intoxication with Mormordica charantia (sorossi). A report of two cases. Sem Hop. 1988;64:2847-2848.
11. Basch E, Gabardi S, Ulbricht C. Bitter melon ( Momordica charantia): a review of efficacy and safety. Am J Health Syst Pharm. 2003;60:356-359.
12. Dans AM, Villarruz MV, Jimeno CA, et al. The effect of Momordica charantia capsule preparation on glycemic control in type 2 diabetes Mellitus needs further studies. J Clin Epidemiol. 2007;60:554-559.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015