Bromelain is an enzyme found in pineapple juice and in the pineapple stem. Bromelain is used for reducing swelling (inflammation), especially of the nose and sinuses, and after surgery or injury. It is also used for hay fever, treating irritable bowel conditions, preventing the collection of water in the lung (pulmonary edema), relaxing muscles,  slowing clotting, improving the absorption of antibiotics, preventing cancer, shortening labor, and helping the body get rid of fat.