I also take ashwagandha for stress. It helps very much but you need to be careful with it so read up on all the side effects. I bought a different brand with more potency and it lowered my blood pressure like crazy. I stopped feeling the effects after a while so I take a 2 week break from the supplement. During that time I use tryptophan.
Ayurvedic Herb Ashwagandha
I have found that one 450 mg capsule of Ashwagandha at bedtime helps to lower my overall stress level A LOT. My friend prefers to take one or two capsules in the morning. It is an "adaptogen" herb that helps to even out cortisol levels, and it really works for us.