The Gymnema Leaves is a shrub that grows in India and Africa. People in India have been using gymnema leaves for thousands of years to try to treat diabetes. The Hindu word for gymnema -- gurmar -- means "sugar destroyer." Gymnema contains chemicals that reduce how much sugar the stomach absorbs. It might also increase the amount of insulin in the body and increase the growth of cells in the pancreas, which is where the body makes insulin. Gymnema Leaves are very effective.