Rhodiola rosea is very effective for improving mood and alleviating depression. Russian research shows that it improves both physical and mental performance, reduces fatigue, and prevents high altitude sickness. In one study, the Rhodiola rosea group decreased proofreading errors by 88% while the control group increased proofreading errors by 84%. Rhodiola rosea's effects are attributed to its ability to optimise serotonin and dopamine levels and to its influence on opioid peptides such as beta-endorphins