1. Age 21-65 years

2. Body mass index ≥ 25kg/m2 at the baseline screening

3. Reporting ≥10 cigarettes per day, on average, for the past 6 months and > 2 year duration of smoking

4. Interest in making a long-term cessation attempt within the next 30-60 days

5. Willingness to receive study medication and standard-of-care smoking cessation supports (nicotine replacement therapy and a smoking cessation app)

6. Ability to adhere to weekly visits and study procedures over the study period (i.e., no plans to move or travel for extended periods)

7. Exhaled CO of >5ppm at baseline

8. Use of an acceptable birth control method for female participants*

9. Ability to read and communicate in English

1. BMI < 25 kg/m2 at screening

2. History of diabetes, diabetes-attributable medical conditions, or HbA1c ≥6.5% at baseline

3. Recent (past 90 days) active suicidal ideation or lifetime history of suicide attempt

4. Current treatment for psychotic disorders or mood disorders with psychotic features (e.g., schizophrenia, schizoaffective disorder, depression with psychotic features), current treatment for bipolar disorder (with or without psychotic features), or current secondary psychosis due to substance use or another medical condition

5. Meeting DSM-5 criteria for a current (past 12 months) substance use disorder other than tobacco use disorder, mild or moderate cannabis use disorder, or mild or moderate alcohol use disorder.

6. Recent (past 30 day) self-report of illicit drug use (excluding cannabis) or non-prescribed opioids; or positive urine screen for illicit drugs. A positive screen for opioids will be allowed if the participant is prescribed an opioid replacement therapy medication and can provide documentation.

7. Past 30-day initiation of psychiatric medications (e.g., SSRIs) or changes to medication dose

8. Treatment with tirzepatide or another GLP-1RA medication in the prior 6 months

9. Current (past month) treatment with other weight loss, diabetes, or smoking cessation medications (varenicline or bupropion; excluding nicotine replacement products)

10. Severe GI disease (e.g., gastroparesis, ulcerative colitis).

11. History of gastric bypass surgery or other surgeries of the stomach

12. Any health condition or treatment/medication that would preclude the use of tirzepatide or NRT, in the opinion of the study physician, including severe cardiovascular disease

13. History of chronic pancreatitis or acute pancreatitis in the last 6 months

14. Currently nursing, pregnant, or anticipating pregnancy

15. History of diabetic retinopathy, proliferative retinopathy, or maculopathy

16. Elevated serum lipase, amylase, bilirubin, or ALP, ALT, or AST (>5x upper limit of normal range)

17. History of malignant neoplasms in the last 5 years, except non-melanoma skin cancer

18. Inability to attend weekly clinic visits as scheduled (i.e., based on travel or work schedule)

19. Currently enrolled in another clinical study involving an investigational product

20. Currently living in the same household as someone taking a GLP-1 medication, or living with a current or former participant in the present trial

21. Planned surgical procedures requiring anesthesia during the planned study medication period

22. Personal or family history of medullary thyroid cancer

23. Personal or family history of multiple endocrine neoplasia syndrome type 2 (MEN 2)

24. Treatment with other weight loss (e.g., phentermine), or FDA-approved, non-NRT smoking cessation therapies (varenicline, bupropion) or FDA-approved AUD medications (naltrexone, acamprosate, disulfiram) or off-label AUD medications (e.g., topiramate) in the past 90 days

25. Any health condition or treatment/medication that would preclude use of tirzepatide or NRT, in the opinion of the site physicians including thyroid enlargement.