In recent years, large number of preclinical and clinical studies support the hypothesis of a link between oxidative stress, anxiety and depression. In search of novel sources of antioxidants in the last years, medicinal plants traditionally used in folk medicine have been extensively studied for their antioxidant activity (AOA). The purpose of this study was to determine the antioxidant activity of the extracts of medicinal plants Valeriana officinalis, Мelissa officinalis, Crataegus monogyna, Hypericum perforatum, Serratula coronata and their combinations Antistress 1 and Antistress 2, which used as food supplements are recommended for chronic fatigue, anxiety and stress. This was done though measuring the Oxygen Radical Absorbance Capacity (ORAC), Hyrdoxyl Radical Averting Capacity (HORAC) and via electrochemical method (EM).