Here is a link to one article http://commonhealth.wbur.org/2013/03/medical-marijuana-mass-rules
Basically eliminates caregivers and the right to homegrow unless you can prove hardship which will be very difficult. And the state can take up to 90 days to decide if you qualify for a hardship and until then you have to go to a dispensary and pay published prices with potentially a discount if you have financial hardship