​Methadone 5 mg is a prescription opioid used to manage moderate to severe pain and to treat opioid dependence as part of a medication-assisted treatment (MAT) program. It is a long-acting opioid that helps reduce withdrawal symptoms and cravings.​ This medicine has a spot with the social occasion of medications called narcotic or opioid analgesics. Methadone is available online for sale as brand names like Dolophine and Methadone. You can also buy Methadone online as a generic version in both oral and injectable forms.