Olive Leaf Extract is derived from the leaves of the olive tree (Olea europaea) and contains compounds, specifically oleuropein, that have demonstrated antioxidant and immune-supporting properties.* Thorne's Olive Leaf Extract contains 18-percent oleuropeins, compounds that have demonstrated antioxidant and immune-supporting properties.* In addition, extracts from olive leaf can help maintain a healthy balance of cytokines in the body.* Cytokines are proteins secreted by cells of the immune system that act as chemical messengers, helping to regulate the body's immune response. Evidence suggests that olive leaf extract may be beneficial for dilating coronary blood vessels, thus supporting blood flow to the heart and helping to maintain already normal blood pressure and cardiac rhythm.**