Naltrexone
"Before starting Vivitrol 7 months ago I had been a heroin addict for a couple of years.  If you're clean for 10-14 days before you get your first shot I can almost guarantee you won't have any horror-story adverse reactions.  This drug saved my life; it took the choice out of my hands, forcing my mind to move on and buying me the time I needed to get my life together.  People are depressed and all because they can't get over not being able to use, that's not a side effect of the drug it's a personal problem.  I didn't experience a single side effect aside from some injection site soreness for 2-3 days after each shot - a small price to pay.  If you need this and can get it, do it."