Rhodiola (Rhodiola rosea) is a popular plant in traditional medical systems in Eastern Europe and Asian with a reputation for stimulating the nervous system, decreasing depression, reducing irritability, enhancing work performance, and improving fatigue. Rhodiola is classed as an adaptogen. An adaptogen has the ability to increase resistance to a variety of physical, chemical, and biological stressors. I often combine Rhodiola with Ashwagandha, Ginkgo, Lemon Balm, Passionflower, Rehmannia, Magnesium, and B Vitamins for stress, anxiety, memory, cognition, irritability, and fatigue, among other health conditions.
Reference: Kelley GS. Rhodiola rosea: a possible plant adaptogen. Altern Med Rev. 2001 Jun;6(3):293-302.