Eligibility Criteria:
Inclusion Criteria:
* The guardian and subject are aware of the study procedures, available alternative treatments, and the risks of participating in the study, and voluntarily sign a written ICF to voluntarily participate in the study.
* Age 14-18 years old (excluding 18 years old) at the time of signing the ICF, with bone age greater than 12 years old.
* Height ≥145cm and body mass index (BMI) \< 30kg/m2 when signing ICF.
* Diagnosis of idiopathic or congenital hypogonadotropic hypogonadism.
* The presence of bilateral pre-gonadal onset testis during the screening period: testicular volume \<4 mL on each side (determined by ultrasound and evaluated by 2 qualified ultrasound specialists authorized by the researchers of the research center).
* The circulating gonadotropin (Gn) level was low (FSH≤1 IU/L and LH≤1 IU/L) during the screening period, and the peak LH value of GnRH excitation test was ≤4 IU/L.
* Serum testosterone T ≤ 1 ng/mL during the screening period.
* The normal range of other pituitary hormones during the screening period (judged by the researcher).
* Lesions detected by MRI on the head within 3 months before or during screening were normal or determined by the investigator to have no impact on the study.
* Consent to the use of reliable contraception (e.g. abstinence, condoms, etc.) by yourself and your sexual partner during the study period and for 3 months after the study drug treatment.
Exclusion Criteria:
There is primary hypogonadism (e.g., Klinefelter syndrome).
* Hypogonadotropic hypogonadism caused by tumor, surgery, trauma, infection, or immune factors in the hypothalamic sella or pituitary gland.
* History of unilateral or bilateral cryptorchidism and the presence of clinically significant testicular lesions (orchitis, testicular tumor, testicular torsion, severe varicocele (grade III), testicular atrophy, obstructive azoospermia, etc.).
* Researchers identified uncontrolled endocrine diseases, including thyroid, adrenal diseases, diabetes, etc.
* History of malignant tumors within 5 years prior to the screening period.
* Patients who have received GnRH, gonadotropin or oral androgen (testosterone, etc.) therapy within 1 month before signing ICF, or who have received testosterone undecanoate intramuscular injection therapy within 1 year before signing ICF.
* History of drug or substance abuse within 1 year prior to signing the ICF, drugs known to impair testicular function or affect the production of sex hormones, or alcohol abuse.
* Abnormal liver and kidney function during screening, i.e. liver function: alanine aminotransferase and/or aspartate aminotransferase higher than 2 times the upper limit of normal (\>2×Upper limit of normal); Renal function: Creatinine and/or urea/urea nitrogen are 2 times higher than the upper limit of normal (\>2×Upper limit of normal).
* During the screening period, patients with systemic diseases (such as metabolic abnormalities, circulatory, digestive, nervous system, etc.) judged by the researchers are not suitable for participation in this study.
* Current thromboembolic disease or known prior history.
* Hepatitis B surface antigen, hepatitis C antibody, HIV antibody and treponema pallidum antibody positive.●
* People who are allergic to the active ingredients or excipients of FSH and hCG drugs or have a history of related allergies, or have a clear contraindication of drug use.
* Participants who participated in other interventional clinical trials and used experimental drugs within 3 months prior to screening.
* Patients with a history of depression or mental disorders.
* Due to risk considerations, the researchers did not consider it appropriate to participate in other situations in this study.