This lesson from Yale's course Addiction Treatment: Clinical Skills for Healthcare Providers covers the three FDA-approved medications for opioid use disorder: methadone, buprenorphine, and naltrexone. The instructor explains how each drug interacts with the mu opioid receptor, contrasting full agonist, partial agonist, and antagonist mechanisms, and walks through dosing, administration requirements, side effects, and duration of therapy for each option. The lecture also covers naloxone's role in reversing overdose. Aimed at clinicians and healthcare providers, the talk uses analogies to make receptor pharmacology accessible and ties the science back to practical prescribing decisions, part of a larger Yale course built around a model patient case and instruction from seven faculty members on screening, diagnosis, and management of substance use disorders.