Efficacy, Metabolism and BMD of the 3-month TP Compared to the 1-month TP in ICPP

Inclusion Criteria: 1. Early appearance of secondary sexual characteristics, specifically breast development in girls before 8 years old or menarche before 10 years old, and testicular enlargement in boys before 9 years old. 2. Gonadal enlargement: pelvic ultrasound shows that girls have at least one ovarian follicle with a diameter \>4mm, and breast development is at least at Tanner stage II; boys have a testicular volume ≥ 4 ml (measured with Prader orchidometer). 3. GnRH stimulation test: LH peak value ≥ 5 IU/L (chemiluminescence method), with an LH peak/FSH peak ratio ≥ 0.6. 4. Bone age (BA) exceeds chronological age (CA) by 1 year or more (based on bone age assessment during the screening period at this center). 5. Accelerated linear growth, with an annual growth rate higher than that of healthy children of the same age. 6. No prior treatment with gonadotropin-releasing hormone agonists. 7. Body weight of at least 20 kg. Exclusion Criteria: 1.Target Diseases: 1. Secondary central precocious puberty: This includes central nervous system abnormalities (tumors or space-occupying lesions, acquired injuries, congenital developmental abnormalities, etc.) and other diseases (congenital adrenal hyperplasia, familial male-limited precocious puberty, McCune-Albright syndrome, etc.). 2. Slow-progressing central precocious puberty: Some children show signs of sexual development before the defined age (7-8 years), but the progression of sexual development and bone age is slow, and linear growth remains within the corresponding percentiles. 2.Treatment History, Medical History, and Concomitant Medical Conditions: 3. Known hypersensitivity to any investigational substance or related compounds. 4. Any chronic disease or treatment deemed by the investigator to potentially interfere with growth or other study endpoints \[including but not limited to: long-term glucocorticoid use (excluding short-term topical use), renal failure, diabetes, moderate to severe scoliosis\]. 5. Girls with a bone age over 12.5 years or menarche ≥ 1 year; boys with a bone age over 14 years (based on bone age assessment during the screening period at this center). 6. Congenital long QT syndrome/12-lead ECG at screening showing QTc ≥ 500 ms corrected by Bazett's formula, excluding other factors causing prolonged QT interval on ECG/12-lead ECG at screening showing QTc between 480 and 499 ms accompanied by unexplained syncope, with no other factors causing prolonged QT interval and no pathogenic mutations. 7. BMI ≥ 95th percentile (same age and gender).