The main purpose of this study is to assess the effect of carbamazepine on the amount of orforglipron in the bloodstream and how long it takes the body to get rid of orforglipron when given orally in healthy study participants. The safety and tolerability of orforglipron and carbamazepine when given separately or together will also be evaluated. The study may last up to approximately 77 days for each participant.

Inclusion Criteria:

• Participants must be overtly healthy individuals, assigned male at birth (AMAB) or individuals not of childbearing potential (INOCBP).

• Have a body weight equal to or greater than 45 kg, and body mass index (BMI) between 18.5 and 35.0 kilograms per meter squared (kg/m²), inclusive, at screening.

• Have a hemoglobin level of

  • at least 11.4 g/dL for individuals assigned female at birth (AFAB) and
  • at least 12.5 g/dL for AMAB.

• Have venous access sufficient to allow for blood sampling.

Exclusion Criteria:

• Have a significant history of or current cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, psychological, or neurological disorders capable of significantly altering the absorption, metabolism, or elimination of drugs; of constituting a risk when taking orforglipron; or of interfering with the interpretation of data.
• Have an abnormal 12-lead electrocardiogram (ECG).
• Have human leucocyte antigen-B (HLA-B)*1502 or HLA-A*3101 allele; participants with other alleles that demonstrate strong evidence of association with carbamazepine-induced hypersensitivity reaction or hepatic impairment may also be excluded.
• Have a history or presence of multiple or severe allergies, or severe post treatment hypersensitivity reactions.
• Have known allergies to carbamazepine or to orforglipron, related compounds, or any components of the formulation.