The purpose of this study is to assess safety, PK, Pharmacodynamic and immunogenicity profile of a single dose of HRS-5817 in obese participants

Inclusion Criteria:

1. Participants aged between 18 to 55 years of age (inclusive)
2. Participants with body mass index (BMI) between 30.0 kg/m2 (inclusive) to 40.0 kg/m2 (inclusive) at screening.
3. Ability to understand the trial procedures and possible adverse events, volunteer to participate in the trial, and provide written informed consent, be able to comply with all the requirements, and able to complete the study.

Negative pregnancy test for women of childbearing potential (WOCBP) at baseline. Men and WOCBP must agree to take highly effective contraceptive methods

Exclusion Criteria:

1. History or evidence of clinically significant disorders 2. Individuals with a weight change of more than 5kg within 3 months prior to the screening.

1. Participant with a history of or current endocrine disorders that may significantly influence body weight (e.g., Cushing's syndrome, hypothyroidism, hyperthyroidism), or with obesity resulting from pharmacotherapy, monogenic mutations, or hereditary obesity syndromes.
2. Any other circumstances (e.g., not suitable for venous access) or laboratory abnormality that, in the investigator's judgment, may increase the risk to the participant, or be associated with the participant's participation in and completion of the study or could preclude the evaluation of the participant's response.
3. Use of any GLP-1 receptor agonists (including but not limited to Liraglutide, Beneglitide, Semaglutide, and Tirzepatide, etc.) or any other prescription medications, OTC drugs and dietary supplements for weight loss (including but not limited to Orlistat, Naltrexone/Bupropion, Phentermine/Topiramate, ect.). within 3 months prior to screening, and no planned use for the study duration.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply