From the Manufacturer:
Since ancient times, black elderberry juice extract has been used as a homeopathic remedy for flu, colds, coughs and respiratory infections. It is wonderfully effective in immune-boosting and prevention. It is the only elderberry extract that contains a unique anti-viral compound called Anti-Viren, as well as antioxidant flavonoids which enhance the immune system by blocking the mechanism by which viruses penetrate the host cells. It has been involved in many favorable clinical studies; data showing that it cuts complete recovery time in half, reduces symptoms, and works in nearly 90% of all cases. It is a very safe product, and in it's liquid form, quite easy to ensure effective cold and flu prevention. It has no contraindications with any known products or medications, and although all research has been extremely positive, it has not yet been evaluated by the FDA.