This study is designed to evaluate the safety, tolerability, PK and PD of GenSci136 in a randomized, double-blind, placebo-controlled trial involving healthy adult participants.

Inclusion Criteria:

1. Male or female, aged 18 to 45 years (both inclusive) at the time of signing informed consent form (ICF).
2. Male body weight ≥ 50 kg or female body weight ≥ 45 kg; BMI between 18-28 kg/m2 (both inclusive) at screening.
3. Males of reproductive age and females of childbearing potential must agree to take highly effective contraceptive methods from screening to the end of the study, and have no plans for conception, sperm donation, or egg donation; females of childbearing potential must have a negative pregnancy test at screening/baseline period and are not breastfeeding.
4. Able to understand the trial procedures, voluntarily participate in the trial, understand and voluntarily sign the ICF, be able to follow all the trial requirements and complete the study.

Exclusion Criteria:

1. Known hypersensitivity to GenSci136 or any of the excipients contained in the GenSci136 formulation, or history of serious hypersensitivity reactions to any drug, compound, food, or other substance, or an allergic constitution.
2. Presence of tattoo, sunburn, scar or any other factors that may interfere with the assessment of the injection site at the intended injection area.
3. A history or presence of other significant metabolic, dermatologic, hepatic, renal, hematologic, cardiovascular, gastrointestinal, psychoneurological, respiratory, and/or other major disease that, in the opinion of the investigator, would affect the evaluation of the study.
4. Any major surgery within 3 months before screening, plan to undergo elective surgery during the study period, or have a history of any surgery that may affect the absorption, distribution, metabolism or excretion of the IMP.
5. Positive result of alcohol breath test, or drug abuser, or use of soft drugs (such as marijuana) within 3 months prior to screening, or use of hard drugs (such as cocaine and ketamine) within 1 year prior to screening, or positive for drug screening [including but not limited to morphine, ketamine, dimethyldioxyamphetamine, methamphetamine, tetrahydrocannabinol, and cocaine].
6. Participants judged by the investigator to be ineligible for other reasons.