I've been taking Rhodiola for around 3 weeks now and can confirm that it is great for upping mood and focus. I mind myself better able to think and problem-solve at work, and feel well energised. This is great. However, I am a pretty poor sleeper and find Rhodiola quite stimulating; so much so, in fact, that it has the effect of disturbing my sleep, which is a shame. Its stimulating properties are such that I am still quite perky when I go to bed, then have trouble getting off to sleep. So, if you suffer from insomnia, Rhodiola may not be for you. If you suffer from fatigue, however, it could be just what the doctor ordered. I plan to stick with it for now and half the recommended dosage of 400mg, to see if this helps.