In regards to fatigue, rhodiola appears to be able to significantly reduce the effects of prolonged and minor physical exhaustion that results in fatigue. This is more related to stress and the 'burnout' effect, or prolonged but low intensity physical exercise. There is some limited evidence that parameters of physical exercise can be improved with rhodiola, but this appears to be limited to untrained persons with numerous studies on trained athletes suggesting that rhodiola does not have an acute ergogenic effect. Despite this, rhodiola appears to be highly reliable in reducing fatigue symptoms and improving symptoms of stress (and secondary to that, well-being) in persons fatigued from non-exercise related stressors.
Rhodiola can improve cognitive functioning in persons who experience a reduction in fatigue, but there is insufficient evidence to support an outright increase in cognition (which should occur in non-fatigued persons) and not enough studies have assessed cognitive decline for conclusions to be made.
Other potential uses of rhodiola include preliminary evidence that it is highly neuroprotective against toxins (requires more evidence) and that ingestion of rhodiola or its active component can reduce stress-induced binge eating in female rats. In the brain, rhodiola appears to be highly serotonergic (increases serotonin) and reduces corticosteroids; the inhibition of monoamine oxidases (MAOs) commonly attributed to rhodiola may not be relevant following oral ingestion of rhodiola, however.
Rhodiola may also promote longevity, with preliminary (non-mammalian) evidence suggesting up to a 20% increase in lifespan secondary to mechanisms that are indepedent of caloric restriction. Although very promising, mammalian evidence is needed to confirm.
One study has found that some commercial Rhodiola products may be diluted or otherwise adulterated.