Bitter melon, also known as balsam pear or kerela, is a plant widely cultivated in Asia, Africa and South America. The fruit, seeds, leaves and roots have long been used in traditional remedies, including some for diabetes. While bitter melon's blood-sugar-lowering properties have been demonstrated in the laboratory and in animal studies, research focusing on the complementary use of bitter melon in people with diabetes is limited, and results are inconclusive. More research is needed to establish efficacy, safety, appropriate dosages and potential interactions -- including interactions with antidiabetic medications.
Forms of Bitter Melon
Bitter melon is available in many different forms. Fresh melon is often sold in specialty Asian markets and can be eaten as a fruit, made into juice, or consumed as a decoction or tea by boiling pieces of the melon in water. All of these have a very bitter taste, as the melon's name suggests. Alternatively, bitter melon can be purchased as a dietary supplement, in the form of an extract, powder or tincture.
Bitter Melon Dosages
Suggested dosages for bitter melon vary widely, depending on the source of the information and the form consumed. For example, tincture dosages range from 10 to 50 ml per day, encapsulated dried powder dosages range from 1 g per day to more than 10 times that amount, and standard extract dosages range from 300 to 600 mg per day, according to a paper published in the February 2002 issue of the "Alternative Medicine Review." If consumed as a juice, dosages range from 50 to 100 ml per day, according to a paper published in the July 2011 issue of "Today's Dietitian." However, there is insufficient evidence from clinical trials to substantiate any of these dosages, and the use of bitter melon is not currently recommended for the treatment of type 2 diabetes.
Pregnant and lactating women should not consume bitter melon. The active chemicals in bitter melon can be transferred through breast milk. The plant has been documented to reduce fertility in both males and females and is contraindicated in pregnancy as it may have abortive properties. Any part of the plant is also contraindicated for people with glucose-6-phosphate dehydrogenase deficiency, a genetic disorder that causes red blood cells to break down in response to illness, medication or certain foods, including bitter melon. Finally, bitter melon should not be given to children, as the covering on the seeds can cause vomiting, diarrhea and death. There have also been two pediatric case reports of hypoglycemic coma and convulsions after ingestion of bitter melon tea.
Other Warnings and Precautions
Bitter melon is generally thought to be well-tolerated in adults, although no large-scale studies have evaluated its safety. Side effects can include diarrhea, stomach pain, abdominal bloating and flatulence. Because larger clinical trials are needed to better understand the effect of bitter melon on blood sugar, it should not be used as a substitute for any diabetes medication prescribed by a doctor. Bitter melon should also not be combined with other diabetes medication, since the additive effect could cause low blood sugar. Always check with your doctor about any complementary or alternative health approaches you are considering, and do not discontinue or change the dose of any medications you are currently taking without your doctor's approval.
- Asian Pacific Journal of Tropical Disease: Antidiabetic Effects of Momorica Charantia (Bitter Melon) and Its Medicinal Potency
- Alternative Medicine Review: Alternative Therapies for Type 2 Diabetes
- Today's Dietitian: Bitter Melon -- Fruit's Role in Diabetes Management Is Promising but Uncertain
- American Journal of Health-System Pharmacy: Bitter Melon (Momordica Charantia): A Review of Efficacy and Safety
- Memorial Sloan Kettering Cancer Center: Bitter Melon
- Nutritional Journal: The Use of Complementary and Alternative Medicines (CAMs) in the Treatment of Diabetes Mellitus: Is Continued Use Safe and Effective?
- PDR for Herbal Medicines; Thomson Healthcare Inc.; 2007