my veins are gone mostly but ill still shoot to where the vein once was and sometimes get a hit. sure, I may not see a vein any longer but I've been shooting for 7 or 8 years myself and just know where those veins were for so many years. esp. when it comes to my biceps and certain parts of my arms/hands.
also, have you used up all veins? feet, hands, neck, etc? many people do not want to go down this road but sometimes it a must if you want to continue shooting.
I've only been away from dope for about a month and just taking Suboxone as I should, so no needle, and I am starting to see my skin return to how it once was; the veins are still taking its time, not even sure if they will return, but some areas feel/look great and its only been a bit more than 30 days.