Sambucol Extra Defence 120ml. A strong Immune system helps to fight infections. Sambucol Extra Defence is a powerful 'non prescriptive' flu treatment. The strongest Sambucol formula yet. Black Elderberries have clinically proven results in reducing cold & flu symptoms. Best of all it's entirely natural & has no known side effects. Sambucol has been clinically shown to cut the length of the flu by 50% with effective scientific trials against Avian (bird) flu & swine flu. T he blend of vitamins & minerals in Sambucol Extra Defence are required by the body for the proper functioning of the immune system helping to keep you healthy all year round. Sambucol Extra Defence is a scientifically tested comprehensive formula containing 9 proven ingredients which provide maximum immune support to help keep you healthy all year round & provide energy for when you need it most.