Bush. Bark, leaves, roots, flowers and fruits are used for medicinal purposes in traditional medicine (diuretic, laxative, anti-infective for cold relief ...) without any scientific evidence on effectiveness.It contains flavonoids (quercetin, isoquercitin and rutin), phenolic acids, terpenes, minerals, tannins. Quercetin is excreted in breast milk in a concentration which increases with diets that contain products like elderberry. In the elderberry as well as other plants are contained endocrine disruptors that could display pro or counter-estrogen activity. Since it has no proven therapeutic benefit, it seems wise to avoid any consumption or doing it in very moderate way during lactation.