As others noted, proving medical benefits has been illegal for a long time. What we do have is the authentic personal experience and testimony to its benefits from hundreds of thousands of users. I know, drug users are not to be trusted; unless it's alcohol or tobacco, then it's ok. But still; you rarely hear users preach the health benefits of crack cocaine, or even alcohol/tobacco.

It does wonders for chronic pain, without the nasty side effects of opiates.

It makes it easier to deal with ADHD/Aspberger traits, without the nasty side effects of amphetamine.

And it seems to have extraordinary cancer curing powers, without long term killing you like chemo.

There's plenty more just a search away...