Species of the genus Sideritis have been used since ancient times in folk medicine, due to their anti-inflammatory, anti-rheumatic and antimicrobial effects. In Greece, as well as in neighboring Turkey, species of the genus are often used as a decoction of gastric, warming, tonic, diuretic, against colds and vasoprotective and are known by the common name "mountain tea". Their biological actions are mainly due to the presence of flavonoids, phenyl ethane glycosides and terpenes. Various species of the genus Sideritis have been found to be active against the AIDS virus, which is due to linearol-type diterpenes. Plants of the genus Sideritis show antimicrobial activity, as well as mild antifungal. The essential oils of plants of the genus have fungicidal and bactericidal action. The content of essential oil is generally low and ranges from 0.05 - 1%. The main components of the essential oil vary depending on the species and the region of origin. They usually belong to the category of monotenic hydrocarbons and / or phenolic constituents and diterpenes.