Use of a GLP-1R Agonist to Treat Opioid Use Disorder

Inclusion Criteria: * Age 18 to 75 years * Diagnosed with an OUD seeking treatment at Caron Treatment Centers (CaronTC) and planning on being enrolled in a residential treatment plan for a minimum of 4 weeks * Women of childbearing potential must consent to use a medically accepted method of birth control or to abstain from sexual intercourse while in the study * Able and willing to provide informed consent prior to any study-related activities * Must be able to read and communicate in English sufficiently to complete all study requirements, including Ecology Momentary Assessment (EMA) Exclusion Criteria: * Age \< 18 or \> 75 years * Women who are pregnant, planning pregnancy, breastfeeding, or unwilling to use adequate contraceptive measures * History of angioedema, serious hypersensitivity reaction, or anaphylactic reaction to liraglutide or another glucagon-like peptide-1 receptor (GLP1R) agonist * Personal or family history of medullary thyroid carcinoma (MTC) or patients with multiple endocrine neoplasia syndrome type 2 (MEN 2) or thyroid nodule * Type I diabetes or history of diabetic ketoacidosis * Type II diabetes mellitus * Hypoglycemia on intake visit (blood glucose \< 70 mg/dL) * End-stage renal failure on dialysis or glomerular filtration rate (GFR) \<30 mL/min per 1.73 square meters or previous renal transplant * Severe hepatic impairment (AST or ALT levels \> 3 times upper limit of normal range) or previous liver transplant * Current or past diagnosis of pancreatitis, gastroparesis, or other severe gastrointestinal disease * Current or past diagnosis of gallbladder disease or gallstones * Serious cardiovascular disease within the past 6 months (e.g. uncontrolled hypertension, heart failure, significant cardiac arrhythmias, myocardial infarction, presence of angina pectoris, symptomatic coronary artery disease, deep vein thrombosis, pulmonary embolism, second- or third-degree heart block, mitral valve or aortic stenosis, hypertrophic cardiomyopathy, stroke) * Severe co-occurring psychiatric disorder (e.g., bipolar disorder, psychotic disorder, schizophrenia) that would, in the opinion of the Principle Investigator or study physician, interfere with participating in the study, such as if the patient needs a higher or different level of care and is going to be transferred out of Caron. * Suicidal ideation within the past 1 month, or history of suicide attempts within the past 1 year, unless participation is cleared by clinician assessment and/or judgement. * Treatment with any investigational drug in the one-month preceding the study * Previous randomization for participation in this trial * Abnormal physical exam findings, vital signs (blood pressure, heart rate, respiratory rate, body temperature), EKG measurements, and safety lab values that are deemed clinically significant by study physician