This trial is conducted in China. This study is a randomized, single-center, open, three-period crossover trial in healthy subjects to compare the PK, PD, and safety of a single administration of GZR4 at different injection sites (abdomen, deltoid region of upper arm, and thigh).

Inclusion Criteria:

• 1. Signing the informed consent form (ICF) before the trial, fully understanding the trial content, process and possible adverse reactions, and being able to comply with the contraindications and restrictions specified in this protocol.
• 2. A Male adult subjects aged 18-55 years old.
• 3. Body mass index (BMI) between 19.0-24.0 kg/m2

Exclusion Criteria:

• 1. Known or suspected hypersensitivity to investigational medical product(s) or related products.
• 2. Participation in a clinical study of another study drug within 3 months prior to randomization.
• 3. Physical examination, vital signs, laboratory examination, imaging examination, 12-lead electrocardiogram and other auxiliary examination results that the researchers considered abnormal clinical significance during screening.
• 4. Donation of blood or blood products (more than 100mL) or significant blood loss (more than 200 mL) within 6 months prior to screening
• 5. More than 14 units of alcohol per week within 3 months prior to randomization
• 6. Smoking more than 5 cigarettes per day within 3 months prior to randomization