by Richard Aiken MD PhD @rcaiken
A systematic review of numerous randomized placebo-controlled studies of Rhodiola rosea showed beneficial effects on physical performance, mental performance, and in mild to moderate depression. For example, one Swedish phase II randomized placebo-controlled study over a six-week clinical trial concluded:
“R. rosea possesses a clear and significant anti-depressive activity in patients suffering from mild to moderate depression. When administered in a dosage of two tablets, each containing 170 mg of extract, daily over a 6-week period, statistical significant reduction in the overall symptom level of depression as well as in specific symptoms of depression, such as insomnia, emotional instability and somatization, could be demonstrated. In higher doses, four tablets per day over a 6-week period, an additional positive effect could be shown. No side-effects resulting from treatment could be detected in any group of the groups”.
Therefore, doses of about 300 – 600 mg were effective in that study.
The mechanism of action may be inhibition of monoamine re-uptake (such as serotonin, dopamine and noradrenaline), enhanced binding and sensitization of serotonin receptors, monoamine oxidase inhibition, and neuro-endocrine modulation. Rhodiola is apparently adaptogenic, meaning that it does its good deeds without disturbing normal biologic functions.
I’m not sure if it is an herb (plant leaf, stem, or flower used for flavoring or medicinal use) or a spice (same as herb but a root). The aerial portion (above ground plant) is used as a food. However, various alternative names for the plant include “root,” such as the “red root” and the powder is a deep red so I assume that the medicinal part is primarily a root and therefore technically a spice.
Rhodiola Rosea 3% Salidroside Powder (100 grams) costs about $18. I use a little less than one eighth of a teaspoon, about 300 mg (a cost of about ten cents). I’m unsure of where this was harvested although it can grow on cold rocky slopes in the USA; it has been suggested to aid those living in very cold stressful environments where it grows, such as Siberia and Scandinavia. It has a shelf life of three or more years.
 Hung, S. K., Perry, R., & Ernst, E. (2011). The effectiveness and efficacy of Rhodiola rosea L.: A systematic review of randomized clinical trials. Phytomedicine, 18(4), 235-244. doi:10.1016/ j.phymed. 2010.08.014.
 Darbinyan, V., Aslanyan, G., Amroyan, E., Gabrielyan, E., Malmström, C., & Panossian, A. (2007). Clinical trial of Rhodiola rosea L. extract SHR-5 in the treatment of mild to moderate depression. Nordic Journal of Psychiatry, 61(5), 343-348. doi:10.1080/08039480701643290.
 Kumar, V. (2006). Potential medicinal plants for CNS disorders: An overview.Phytother. Res. Phytotherapy Research, 20(12), 1023-1035. doi:10.1002/ptr.1970
 My source for this is from Bulk Supplements (www.bulksupplements.com) – I order from Amazon and guided in my selection in part by happy consumers who have tried it and like it on some basis.