Bitter melon tea contains an ingredient similar to insulin that is claimed to lower blood sugar, WebMD explains. However, research as of October 2015 has been inconclusive in proving its efficacy. Some studies show that bitter melon also improves glucose tolerance in people with type 2 diabetes.
Because bitter melon, along with juices, tea and extracts from it, can lower blood sugar levels, diabetics taking medications to do the same must monitor their blood sugar levels carefully. In addition, bitter melon shouldn't be taken within two weeks of surgery, according to WebMD. Pregnant and breastfeeding women and people with glucose-6-phosphate dehydrogenase deficiency should also avoid bitter melon, which is also known as African cucumber, balsam pear, bitter apple and wild cucumber.