Self-injection system allows a user to inject a drug from a cartridge carrying unique identification information, into any one of a plurality of injection sites. Tissue at each injection site is associated with at least one injection parameter, such as flow-rate, that is different for each site. A scanner reads the identification information of the cartridge and cooperates with a central processing unit to determine the validity of the drug in order to permit an injection procedure to commence. The central processing unit has a memory for storing the different injection parameters and controls a drive unit for driving fluid from the cartridge and through a needle into the selected tissue, at the injection parameter that is associated with the user selected tissue for the injection.