The vegetable, Karela, is a natural blood purifier, and activates the spleen and liver. This powder is consumed in small amounts and can be mixed with soups and gravies. Karela powder has been used in India for centuries as a natural way to deter or reduce the effects of diabetics.

It contains a lectin that has insulin-like activity due to its non-protein-specific linking together to insulin receptors. This lectin lowers blood glucose concentrations by acting on peripheral tissues and, similar to insulin's effects in the brain, suppressing appetite. This lectin is likely a major contributor to the hypoglycemic effect that develops after eating bitter melon.