Inclusion Criteria:

• adults who have been enrolled in the multidisciplinary metabolic and bariatric surgery program at the UK HealthCare Weight Loss Surgery Clinic and are scheduled to receive laparoscopic or robotic sleeve gastrectomy, or gastric bypass surgery
• BMI greater than or equal to 40 kg/m2 with one or more obesity-related comorbidities
• have demonstrated abstinence from any form of nicotine use, confirmed by serum nicotine and metabolite testing
• enrollment in the ADORE Bariatric Tissue Bank (IRB #69767)

Exclusion Criteria:

• any contraindication to the use of tirzepatide (per package insert)
• Personal or family history of medullary thyroid carcinoma
• Patients with Multiple Endocrine Neoplasm syndrome type 2
• Hypersensitivity to tirzepatide
• History of pancreatitis
• Type 1 Diabetes
• patients with active, untreated or symptomatic cholelithiasis or jaundice
• consistent use of a GLP-1 or GLP-1/GIP receptor agonist, over the past 90 days
• diagnosed autoimmune disease
• current use of immunosuppressive agents or use within the past 30 days
• moderate or severe substance use disorder according to DSM-5 criteria
• uncontrolled significant psychiatric disorder as assessed by specialized bariatric psychologist
• female participant who is pregnant, breast-feeding, or intends to become pregnant with in 1 year following surgery
• a prisoner