Bitter melon fruit is POSSIBLY SAFE for most people when taken by mouth in the short-term. The safety of long-term use (beyond 3 months) is not known. There also is not enough information about the safety of consuming other parts of the bitter melon or applying bitter melon to the skin.
Taking bitter melon along with diabetes medications might cause your blood sugar to be too low since both decreases blood sugar levels. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.