Buprenorphine is an opioid used to treat opioid use disorder, acute pain, and chronic pain. It can be used under the tongue (sublingual), in the cheek (buccal), by injection (intravenous), as a skin patch (transdermal), or as an implant. For opioid use disorder, it is typically started when withdrawal symptoms have begun and for the first two days of treatment under direct observation of a health-care provider. The combination formulation of buprenorphine/naloxone (Suboxone) is recommended to discourage misuse by injection. Maximum pain relief is generally within an hour with effects up to 24 hours.