Methadone is classified as a full opioid agonist. It works by binding to the same receptors in the brain and spinal cord that are activated by other opioids, such as heroin or morphine. However, methadone's effects are longer-lasting, which helps to reduce withdrawal symptoms and cravings. Methadone is a key component of MAT, a comprehensive approach to the treatment of opioid addiction that combines medication with counseling and behavioral therapies.