Eleutherococcus : Some species, notably  E. senticosus  (Siberian ginseng), are used for  herbal medicine . Rhodiola rosea : Rhodiola rosea  may be effective for improving  mood  and alleviating  depression . Pilot studies on human subjects [2] [3] [4]  showed that it improves  physical  and  mental   performance, and may reduce  fatigue