^^Idk maybe,but still i dont think ppl should get on forums and start recommending things they have no clue about.
Naltrexone is used to prevent relapse by blocking the receptors,is given to long term users and its a full antagonist,meaning its has no(positive) mood altering properties whatsoever,and pretty much no upside to it(unlike bupe,which is a partial agonist).
Youre supposed to be clean AT LEAST 4-5 days off of hard opiates to be safe to take it,and at least 3-4 days off weaker ones(like codeine).