I think that cannabis is one of the best alternatives in medicine. Even if we compare most painkillers ( pills, not opioids) and cannabis, I believe that cannabis is better because it's natural. And it's already proven that medical marijuana in the right amount has a positive impact on health and helps a lot of people with chronic diseases and pain. On this site,
http://california-wellness.org are many articles about cannabis, its' medical usage, benefits, etc. I often read articles there, and as for me, it's a great source of information.