• English speaking adults aged 18 and above

• DSM-5 diagnosis of opioid use disorder, severe

• Initiated sublingual buprenorphine (SL-BUP) treatment within 60 days of enrollment

• Attained stable dosing of SL-BUP of 16mg or greater for 30 days prior to enrollment

• Anticipating continuation of SL-BUP for the duration of the trial

• Agreeable with bringing SL-BUP prescription to visits to allow study team to conduct a dose count

• Willing to grant study team permission to communicate about SL-BUP treatment with community prescriber via completion of 42 CFR release

⁃ Individuals with any of the following will be excluded:

• DSM-5 diagnosis of any current substance use disorder excluding opioid, cannabis or tobacco

• Active psychosis, active suicidality or homicidality or any psychiatric condition that impair ability to provide informed consent

• Any current or lifetime diagnosis of eating disorders

• BMI\<25mg/kg2

• Current or lifetime diagnosis of Type 1 or Type 2 diabetes

• Personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2

• Use of any GLP-1 agonist medications in the prior 3 months

• Anticipating receipt of any GLP-1 agonist medications during the trial

• History of angina pectoris, coronary heart disease, congestive heart failure, inflammatory bowel disease, chronic obstructive pulmonary disease, bariatric surgery, idiopathic pancreatitis, diabetic gastroparesis

• Liver function test greater than 3 times upper normal limit

• Renal impairment as indicated by eGFR of \<60

• History of hypersensitivity or allergy to semaglutide

• Pregnant or breastfeeding

• Anticipated to participate in a concurrent drug trial

• Any other reason or clinical condition that the investigators judge may interfere with study participation and/or be unsafe for a participant