Contemplating osha root

My latest fascination is with osha root. I really want to get some and try it out when the season of sickness comes upon us. From what I have read, this plant may be invaluable for asthma, which has plagued me off and on all of my life. I wish this was a local herb, but I'm on the wrong side of the country. I have read that it is impossible to cultivate and that the wild supply may be dwindling, which is just terrible. My conservationist side says find something else, and my inquisitive side says try it at least, in a small amount. It's like being both pro life and pro choice, in a different subject area. Will I give in to inquisitive temptation? Most likely I will, scolding myself at the same time I'm feeling gratitude for respiratory relief.