Planta Medica - PLANTA MED , vol. 75, no. 09, 2009
Evidence based efficacy of adaptogens in fatigue
A. Panossian, G. Wikman

Abstract
The aim of this systematic review was to assess the level of scientific evidence of efficacy of adaptogens on cognitive functions in fatigue. The results were evaluated by Natural Standards Evidence-Based Validated Grading Rationale (NSR) and by European Medicines Agency Assessment Scale (EMEAS), as recommended. There is strong scientific evidence (grade A) that treatment with Rhodiola SHR-5 extract is able to improve cognitive performance across „attention“ tasks. These results were observed in three randomized, placebo controlled, and double-blind clinical trials (257 patients). In addition, good (grade A level) scientific evidence was estimated in chronic fatigue syndrome. Grade B level was also documented for Schisandra, which was shown to increase endurance and mental performance in 2377 patients over eight trials. Grade B level can also be accepted for Eleutherococcus in 729 patients with mild fatigue and weakness. Grade C level of evidences, mainly due to conflicting results obtained in different studies, is related to Ginseng, which can improve cognitive functions. In conclusion, adaptogens can be defined as a pharmacotherapeutic group of herbal preparations increasing tolerance to mental exhaustion and to enhancing attention and mental endurance in cases of decreased performance, such as in fatigue and in sensation of weakness.