Naltrexone is a once a month injection that is used in the treatment of both opiate and alcohol addiction.  It can help significantly reduce cravings for opiates and/or alcohol, and is used to help prevent relapse of either addiction.  Naltrexone is not a narcotic or an opiate, it is an opiate blocker or antagonist.  Once injected, the naltrexone molecules sit in and fill up the opiate receptor sites.  This significantly reduces cravings (many clients even report their cravings are eliminated), and helps prevent relapse because one will not have a euphoric or ‘high’ effect, if they use opiates.