Gaia Herbs, Olive Leaf, 120 Vegetarian Liquid Phyto-CapsValue Size Single Herbs Supports a Healthy Immune Response Dietary Supplement Olive Leaf Olive Leaf has the unique ability to support immune function while also offering the body protection from free radical damage. Because of this antioxidant property, Olive Leaf shows promise in supporting cardiovascular health. Gaia Herbs' fresh picked whole Olive Leaf is gently concentrated into a superior quality extract.