This trial is conducted in China. The aim of the trial is to evaluate the safety and tolerability of GZR18 injection in healthy subjects following single dose and once-weekly dose for 2 consecutive weeks until reaching the target dose.

Inclusion Criteria:

• 1. Subjects sign informed consent voluntarily.
• 2. Chinese adult subjects, male or female.
• 3. Age 18-55 at screening (both included).
• 4. At screening and baseline, 19.0 kg/m2 ≤ BMI ≤ 26.0 kg/m2 (male ≥55.0 kg, female ≥45.0 kg).
• 5. Female subjects were human chorionic gonadotophin (HCG) negative at screening and baseline.

Exclusion Criteria:

• 1. History of dizziness with blood and needles.
• 2. Known or suspected allergy to study related products; or a history of drug and food allergies; or a history of allergy-related diseases.
• 3. Participants who participated in other clinical trials and were given the investigational drug or medical device intervention within 90 days prior to screening.
• 4. Blood donation, surgery, or trauma with significant blood loss (more than or equal to 400 mL, except for menstrual blood loss in women) within 12 weeks prior to screening.
• 5. Any clinically significant medical history judged by the investigator, including but not limited to: lung, gastrointestinal, liver, nervous system, kidney, genitourinary and endocrine, skin, or blood disorders, especially a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 , and a history of pancreatitis (acute or chronic).
• 6. At screening or baseline, physical examination showed clinically significant abnormalities judged by the investigator.