Pharmacology and Core Efficacy (GnRH Agonists) Mechanism of Action: Initially, the drug briefly stimulates the pituitary gland to secrete gonadotropins; however, with continued administration, the pituitary gland undergoes desensitization, leading to the suppression of gonadal function. Consequently, testosterone and estrogen levels drop to the range associated with pharmacological castration. Andrology: Hormone-Dependent Prostate Cancer Used for endocrine castration therapy in cases of advanced or metastatic prostate cancer. It serves as an alternative to surgical orchiectomy, rapidly lowering testosterone levels, reducing tumor size, and alleviating bone pain and urinary obstruction. The long-acting 3.75 mg formulation is administered via intramuscular injection once per month. Gynecology: Three Primary Indications ① Endometriosis (Stages I–IV): Suppresses estrogen production, inducing atrophy of ectopic endometrial tissue. This helps alleviate dysmenorrhea (menstrual pain) and pelvic bleeding, and reduces lesion size prior to surgery (treatment duration: ≤ 6 months). ② Uterine Fibroids: Reduces fibroid volume prior to surgery, thereby minimizing the risk of massive intraoperative hemorrhage and improving anemia (it is the preferred treatment for patients with Hb < 8 g/dL). ③ In Vitro Fertilization (IVF) Support: Suppresses endogenous ovulation and synchronizes follicular development, thereby preventing premature ovulation and increasing the success rate of oocyte retrieval. Pediatrics: Central Precocious Puberty Indicated for true precocious puberty in girls under 9 years of age and boys under 10 years of age. It suppresses the secretion of testosterone and estradiol, thereby delaying accelerated bone maturation and preventing premature epiphyseal closure, which could otherwise compromise final adult height. Administered via intramuscular injection once per month. Fitness Community: Niche Applications In the bodybuilding community, it is occasionally used during competition preparation to lower endogenous testosterone levels, control estrogen-related side effects, and temporarily suppress gonadal function. Indications ✅ Approved Clinical Use Men: Hormone-dependent locally advanced / metastatic prostate cancer; Women: Severe endometriosis, symptomatic large uterine fibroids, downregulation and ovulation induction during IVF cycles; Children: Diagnosed central precocious puberty (girls < 9 years, boys < 10 years); Special Cases: Endocrine therapy for select hormone-sensitive breast cancers (as prescribed by a physician).
