The bitter melon (Momordica charantia), a slender vine plant, is consumed as a food and also as a medicine in several tropical regions including Africa, Asia, South America and the Caribbean. In living up to its name, all parts of the bitter melon plant---including the fruit, leaves and stem ---are bitter in taste. Bitter melon exhibits many medicinal properties and is widely used by natural health practitioners to treat diabetes, viruses, colds and flu, cancer and tumours, high cholesterol and psoriasis. However, the bitter melon is also reported to cause several adverse side-effects including hypoglycaemic coma, hemolytic anaemia, allergies, drug interactions and infertility.
Several in vivo studies, according to the Rain Tree website, have established the hypoglycaemic properties of bitter melon. Many chemical constituents in bitter melon---including charantin, polypeptide P and vicine---are responsible for its blood sugar lowering capabilities. Yet bitter melon is contraindicated in diabetics, who should consult a physician prior to using it, else they suffer the risk of suffering from hypoglycaemic coma, a glucose deficiency that leads to unconsciousness among other deteriorating health conditions. Regularly monitor blood sugar levels if you consume bitter melon, as the dosage of insulin medication may need adjusting. Children have reportedly experienced hypoglycaemic coma after consuming a tea prepared from bitter melon, according to the Drugs.com website.
According to the Wellness website, patients with glucose-6-phosphate dehydrogenase (G6PDH) deficiency should not consume bitter melon, as they risk experiencing hemolytic anaemia and "favism," which is the first sign of hemolytic anaemia. Symptoms of favism include headache, fever, abdominal pain and coma.
In vivo studies have proven that the fruit and leaf of bitter melon has an anti-fertility effect in female animals and negatively affects sperm production in male animals. Bitter melon induces abortion, can affect your ability to get pregnant and is not recommended during pregnancy or breast-feeding because of the risk of birth defects or spontaneous abortion.
Avoid bitter melon if you are allergic to the gourd or melon (Cucurbitaceae) plant family of melons which include the Persian melon, honeydew, casaba, muskmelon and cantaloupe. Telltale signs of an allergic reaction to bitter melon are quite evident and may manifest as skin rash and itching or shortness of breath.
Bitter melon is also known to have adverse interactions with other medications. Consult your physician prior to consuming bitter melon if you are on drug therapy for any health condition. Bitter melon interacts with drugs that are metabolised by the liver, fertility and anti-fertility agents, immune system suppressants or medications used to treat parasites.