Ashwagandha maximizes the ability of the body to resist stress. It enables the body to reserve and sustains vital energy throughout the day while promoting sound and restful sleep at night. It is considered one of the best herbs for calming vata and for revitalizing the male reproductive system. It is used to support energy, potency, and a healthy libido in men. Therefore it is said to bestow upon its user the vitality and strength of a horse.