Hydroxytyrosol (3,4 dihydroxyphenylethanol; 3,4-DHPEA or HT) represents one of the most abundant phenolic compound in extra virgin olive oil (EVOO). It plays a significant role in cardiovascular diseases (CVDs) protection and its metabolites are able to prevent the endothelial dysfunction commonly present in atherosclerosis. We conducted a randomized, placebo-controlled crossover trial in order to verify the role of a new pharmaceutical formulation containing HT for the prevention of oxidative stress related to CVD. Protective Oxidative stress biomarkers, like thiols groups and total antioxidant status, were significantly increased, while pro-oxidant were drastically reduced. Significant up-regulation of superoxide dismutase-1, encoding for a cytoplasmic antioxidant enzyme, was observed. These results could be associated with the significant increase in the plasma concentration of HT. Our data support the hypothesis that 15 mg/day of HT could prevent oxidative damage and related CVD. The new formulation could be proposed to EFSA to obtain “health claim” according to Regulation (CE) n. 1924/2006, related to the following nutritional and health indications: “reduction of oxidative stress”, “maintenance of normal blood HDL-cholesterol concentrations”, “anti-inflammatory properties”, “antioxidant properties”, and “contribution to body defense against external agents” .