For a guy in his early to mid-20's, a restart has about a 50/50 chance of working, maybe a little less. For a guy over 30, the odds are much lower. Personally, I've never seen a man over 30 be successful with a restart long term or rather successful to where his testosterone is anywhere near optimal. Higher than it was? Sure, but far from optimal. Anyway, might be worth a shot, never hurts to try, just understand there's no guarantee with this type of thing.