Elderberry - Sambucus nigra L. - a plant belonging to the Adoxaceae family, which can be found in areas of western and central Europe, as well as in some regions of Asia and the northern part of Africa. It is a tall shrub that is characterized by white flowers gathered in large umbels and fleshy and shiny fruits, which are distinguished by their dark purple color. The most commonly used parts of the plant are the fruits and flowers of elderberry, which are used both in cosmetics, food products and dietary supplements. Elderberry is appreciated for its wealth of valuable substances - it is a source of vitamins and minerals, as well as other valuable compounds, including polyphenols or anthocyanins, the content of which is standardized in the extract from the plant used in the OstroVit preparation.