While animal tests have suggested a variety of beneficial effects for Rhodiola rosea extracts, only for depression is there scientific evidence for Rhodiola components having anti-disease benefits in humans. A clinical trial showed significant effect for a Rhodiola extract in doses of 340–680 mg per day in male and female patients from 18 to 70 years old with mild to moderate depression.
Rhodiola rosea extract SHR-5 exerts an anti-fatigue effect that increases mental performance, particularly the ability to concentrate in healthy subjects (Darbinyan et al., 2000; Spasov et al.,2000b; Shevtsov et al., 2003) and burnout patients with fatigue syndrome (Olsson et al., 2009). Rhodiola significantly reduced symptoms of fatigue and improved attention after four weeks of repeated administration (Olsson et al., 2009).
Olsson, E.M.G., von Schéele, B., Panossian, A.G., 2009. A randomized double-blind placebo controlled parallel group study of SHR-5 extract of Rhodiola rosea roots as treatment for patients with stress related fatigue. Planta medica 75,105-112.
Taking the mental and physiological parameters together, the study does not reveal any demonstrated difference in efficacy, or even a minor consistent trend in favour of one of the groups. (Both groups performed highly significantly better compared with the placebo group.) This seems to imply that both doses in the trial are either close to the optimum dose or quite far from it. If one attaches importance to the well-established use in Russian medicine together with a large number of clinical studies of various levels of evidence, the optimum dose will be within a range of approximately 0.5 to 3 times the lowest dose in this study. These facts clearly indicate the first possibility, i.e. the optimum single dose of S HR-S is close to the doses used in this study.
There have been a variety of academic studies regarding the effectiveness of this plant for various medicinal applications. The majority of the claims regarding mental health benefits have been supported by experimental trials. For example, a study at the Kaunas University of Medicine confirmed it to have the mental health, acuity, and antioxidant characteristics. A double-blind study at the Volgograd Medical Academy demonstrated a noticeable reduction in fatigue for those participating in the study. The commercial popularity of this supplement has lead to an increase in serious academic research about its applications. Countless studies have demonstrated a variety of possible health benefits that are associated with supplemental use of Rhodiola Rosea.