Olympian Labs Olive Leaf Extract contains the active phenolic compound known as oleuropein. Oleuropein (pronounced oh-lee-or-oh-pin) is a bitter substance that scientists have isolated from the olive leaf. Oleuropein's action begins when it breaks down in the body to elolenic acid (in the form of calcium elenolate; a calcium salt). Olive leaf extract may also help boost energy levels and is an excellent companion to herbs such as Echinacea and Goldenseal.