Samidorphan was developed as a sublingually bioavailable µ-opioid receptor antagonist. This drug participated in clinical trials for the treatment of Schizophrenia, Alcohol Dependence, and Binge Eating Disorder. The oral dose pharmacokinetics, safety, and tolerability of samidorphan were evaluated in phase II double blind, placebo-controlled, randomized studies in healthy adults. In addition, the combination of samidorphan (SAM) with buprenorphine (BUP) was studied in phase III clinical trial in patients with major depressive disorder (MDM). It was shown that the long-term treatment did not reveal any new safety findings and confirmed that the risk of abuse and dependence with BUP/SAM was low.