Long term use of Ashwaganda?

I started using this several months ago for severe adrenal/thyroid symptoms I was having. Along with lots of other UNY suggestions I have found myself to be doing SO much better. I'm afraid to stop doing anything I'm doing but was concerned about long term use of this herb. I can't find much info on the safety of long term usage.. Does anyone have any info on this. I mix it with my Greenfood and Acerola Cherry powder 3x a day. Thanks for any info you might have!!! Krik