The fact that a substance has unwanted effects does not mean it cannot be used constructively as a medicine. Those are some pretty substantive problems that would need to be outweighed by a significant benefit.
The best discussion is here, at the NIH:
link
The NIH discussion skips a couple points I usually make such as smoking MJ is an even worse way to get a consistent dose of the active chemicals and know what else you are getting than what they are discussing. If you read studies on other drug trials, there is a "dosage" section. It is usually 2-3 sentences. For smoking MJ, the dosage section is usually a page or two, sometimes longer. This calls into question whether or not people using MJ are actually doing what was described in excruciating detail in the study in order to get similar effects.
Studies of smoking MJ use a specific curated strain of the plant for consistency across studies. That is not what you buy at a dispensary. If a pharmaceutical company gave you a prescription pill with the variability in the studies (let alone the difference between studies and what is given out at dispensaries), you would sue the crap out of them.
It also doesn't point out that in all the studies I have read, purified THC used like an actual medical treatment doesn't have side effects like getting you high any more than ibuprofen (a small number of people get ill, feel slightly woozy, or are allergic). Most of the euphoric effects of smoking MJ do not come from THC, they come from the other substances (wide range) you get in various strains, those substances in combination with THC, and oxygen depravation from smoking in combination with THC.
My favourite thing to do when people say "studies show" is to ask them which studies (rarely do they know) and exactly what do they say (not someone's Twitter interpretation).
Also … deliberately inhaling a significant amount of smoke on a regular basis is bad for you. ;)
