Naltrexone is a medication approved by the Food and Drug Administration (FDA) to treat both alcohol use disorder (AUD) and opioid use disorder (OUD) . It is used in medication-assisted treatment (MAT) to treat both opioid and alcohol use disorders. Naltrexone blocks the euphoric and sedative effects of drugs such as heroin, morphine, and codeine, and it works differently in the body than buprenorphine and methadone, which activate opioid receptors in the body that suppress cravings. Naltrexone binds and blocks opioid receptors and is reported to reduce opioid cravings. It is also used to help narcotic dependents who have stopped taking narcotics to stay drug-free and to help alcoholics stay sober. Naltrexone is taken as a tablet, and the length of the course will depend on each persons needs and situation. It can also be administered via an implant. Naltrexone treatment is more likely to be successful if its part of a comprehensive treatment program that includes counseling, alternative therapies, and a positive network of peers and friends, and a support group.