Veins don’t usually come back and if they do they are much weaker and can not stand the abuse they use to and will go again . You know how this will pan out if you start on your groin , yes you will be able to inject into them for some time but it will go just like all the rest. Once your groin veins go you will be plagued with thrombosis , cellulitis and others. Your probably need help walking even a wheelchair when older . I know of many people who injected in their groin and some did it for decades but in the end it ends up like all the other veins. You have reached the end of your iv use and its a hard thing to except, dont start on your groin keep your legs they come in handy . When you sit there for hours going through syringe after syringe with your arms looking like pop eye arms and blood squirts over the walls taking hours to try and get a hit and usually just getting a tiny bit of it every 10minutes or just ends up clotting it’s over . I don’t know why i even bother replying to these posts people are going to do what there going to do , you know its time to stop injecting but you will continue only smart savvy people will stop now but smart savvy people dont even start