Ashwaganda is great, but there are few things to be cautious about. People often report, that after some time of regular usage they feel kinda emotionless. Cheaper brands don't control sources and a lot of Indian supplements may have higher levels of heavy metals which might not be bad short term, but if you decide to take it regularly for a long time I would pick some trusted brands that test their sources for heavy metals and contaminants. KSM-66 is a nice patented version of ashwaganda, but still doesn't guarantee purity. Ashwaganda is an adaptogen and there are a lot of them with different effects that are also individual, so if it's not going to work you can try a different one with a similar calming effect.