The best place to get ginseng for tea or extract is deep in the woods, on north facing hillsides.
Wild Ginseng is the best. There is a harvest season, so check your State regulations on that.
Lots of post here showing pictures, and how to hunt it details.
I harvest my own wild root and dry it and then put a few roots in my Nutri Bullet and it turns it into sort of a coarse grind in just a few seconds.
I keep it in a container on my home office desk and eat a pinch or two daily.
I do at times put it in with some hot green tea and drink the tea and eat the root.
I could not really recommend a place to buy a commercially produced product. I have never done that. It would most likely be a much inferior product compared to true wild ginseng.
Good Luck !
TNhunter
