What it is: Ashwagandha is an herb from India that has been used as a general tonic for ages.How it works: Like ginseng and rhodiola, ashwagandha has historically been used for its adaptogenic properties and helps energy metabolism and the health of the nervous system. While some adaptogenics have a more stimulating effect on the nervous system,ashwagandha’s properties have the opposite effect, while at the same time supporting energy metabolism..In which products you can find it: