How much medicine can I have with my card? You may possess a maximum of two-and-a-half ounces of usable cannabis. All FAQ’s from General Are there different kinds of medical marijuana? Can I drive while using medical marijuana? How much does it cost to obtain a medical marijuana card? Is the Rhode Island Medical Marijuana Card recognized by other states? Is there marijuana which won’t get me high? What forms does marijuana come in? What is a caregiver? What is the impact of possessing a medical marijuana card on employment? What should I tell my employer if I am subjected to a drug test? Where can I use my medication? Where do I get medical marijuana medication? Who may use medical marijuana?