The main purpose of this study is to evaluate the efficacy and safety of retatrutide in relieving chronic low back pain in participants who have obesity or overweight. Participation in the study will last about 80 weeks.

Inclusion Criteria:

• Have a history of axial-predominant low back pain
• Have pain that is restricted to the low back or with a referral pattern limited to the proximal legs
• Have a body mass index (BMI) ≥27 kilograms per square meter (kg/m2) at screening
• Have a history of at least 1 self-reported unsuccessful dietary effort to lose body weight

Exclusion Criteria:

• Have a non-axial origin low back pain
• Have had botulinum or steroid injections to the spine within 1 year of screening
• Have had trigger point injection to the spine within 6 months of screening
• Have a self-reported change in body weight >5 kilograms (kg) (11 pounds) within 90 days prior to screening
• Have been taking drugs to promote body weight reduction, including over-the-counter medications, within 90 days prior to screening
• Have a prior or planned surgical treatment for obesity
• Have Type 1 Diabetes, Type 2 Diabetes, or any other type of diabetes

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

Data are available 6 months after the primary publication or approval of the indication studied in the US and EU, whichever is later. Data will be indefinitely available for requesting.

A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.