Sambucol is a unique black elderberry extract rich in immune supporting flavonoids. Flavonoids are powerful, natural antioxidants that are thought to work to protect the body’s cells from the potential damage caused by free radicals. Certain flavonoids anthocyanins are found primarily in the pigments of dark blue and deep purple fruits such as the black elderberry. It is these that have a remarkable ability to stimulate the body’s immune system.