This study is testing a new medicine, NNC6989-0001, to test it is safe and tolerable for healthy people living with overweight or obesity. NNC6989-0001 is still being tested in studies and is not yet available for prescription by doctors. In this study, participants will receive either NNC6989-0001 or a placebo; which treatment each participant receives will be decided by chance.

Inclusion Criteria:

• Male or female of non-childbearing potential.
• Age 18-55 years (both inclusive) at the time of signing the informed consent.
• Body mass index (BMI) (at screening) ≥ 25.0 and ≤ 34.9 kg/m^2 for Part A (SAD part) and BMI (at screening) ≥ 25.0 and ≤ 39.9 kg/m^2 for Part B (MAD part).
• Considered eligible based on the medical history, physical examination, and the results of vital signs, electrocardiogram, and clinical laboratory tests performed during the screening visit, as judged by the investigator.

Exclusion Criteria:

• Any condition, which in the investigator's opinion might jeopardise participant's safety or compliance with the protocol.
• Any clinically significant body weight change (≥5 % self-reported change) or dieting attempts (e.g., participation in a weight reduction program) within 90 days before screening.
• Treatment with any GLP-1 RA or a medication with GLP-1 activity within 90 days before screening
• Use of prescription or non-prescription medicinal products within 14 days before screening. This includes over the counter medicines such as laxatives, mineral oil, and fat-blocking supplements. Routine multivitamin/mineral supplements at labelled daily doses are permitted; other non-prescription supplements (e.g., high-dose vitamins, weight-loss supplements) are not permitted. Occasional use of over-the-counter acetaminophen or NSAIDs at their labelled doses for mild pain is permitted.

According to the Novo Nordisk disclosure commitment on novonordisk-trials.com

Sponsor staff involved in the clinical trial is masked according to company standard procedures.