Senna Leaves Senna Leaves Senna is an FDA-approved over-the-counter (OTC) laxative. A prescription is not required to purchase senna. It is used to treat constipation and also to clear the bowel before diagnostic tests such as colonoscopy. Specifications Botanical NameCassia Angustifolia Common NamesSenna Purity99%, 99.5% TypesSenna Leaves Prime 1,2,3,4 & 5 , Senna Leaves Powder, Senna Leaves Cut, Senna Pods, Senna Seeds, Senna Stems GMONon Genetically Modified OriginIndia