Minnesota's law has plenty of restrictions including not smoking it. It can only be used for certain conditions. The bill was signed but hasn't happened yet. Here is a site to read about it all.

http://www.reuters.com/article/2014/...0E91TN20140529

It starts in July, 2015. Toward the end of the article it lists the few conditions to be eligible of which they say perhaps only 5,000 people will qualify.