Of course, as long as it is not moldy, the main effective component of American ginseng is saponin, which will volatilize. If it is wet, it will definitely not evaporate so quickly, and the most feared thing is mildew.
In fact, it is best to buy the whole ginseng and cut it off when you want to eat it, so that the saponins will not volatilize. If you buy one, it doesn't have much effect.