“Dolophine”, as Methadone is mainly sold commercially, is a synthetic opioid drug which is present in withdrawal treatments from opioids, mainly heroin. Like other opioid pain-killers, it has the side effect of addiction when it is used frequently.
Methadone is a pain reliever like other opioid drugs (derivatives of the poppy plant), such as morphine, oxycodone and codeine. It has been prescribed for decades for people to deal with pain after chronic illnesses, injuries or surgeries.
Since methadone blocks the effects of any other opioid drugs, it has become a most sought-after withdrawal management medication, because it´s not as strong as heroin, albeit tends to remain in the body system for longer periods of time (roughly over twenty hours). It is also less sedating and less harmful.