heroin addiction, as with all addictions, is a chronic disease.  That means it will never "go away", however it can be arrested.  Methadone is one way to stem the physical withdrawals of heroin.  There are other methods as well, such as suboxone, buprenorphine, etc.  The best way to arrest any addicition is to get professional counceling as well as work a program of relapse prevention. The most common program is Narcotics Anonymous for heroin, however there are many alternatives that any addiction councelor can tell you about.