Nature`s Way Rhodiola Rosea extract is standardized to 3% rosavins and 1% salidroside which has been shown to produce the most beneficial results in clinical studies. Rhodiola an adaptogen comes from Arctic regions and has been shown to increase energy physical endurance and well-being. It is also proven to prevent sickness in high altitudes. In Russia Rhodiola has been known to combat the harsh Siberian climate and the stressful life. There are some 50 species of rhodiola but it is the fragrant root of the species Rhodiola rosea that is used medicinally. Rhodiola rosea grows throughout the mountainous regions in the higher latitudes and elevations of the Northern hemisphere.