Glerelin Injection contains Leuprolide acetate 22.5 mg, a synthetic nonapeptide analog of gonadotropin-releasing hormone (GnRH). It acts as a potent GnRH agonist, initially stimulating and subsequently downregulating pituitary gonadotropin secretion, leading to decreased production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This results in reduced gonadal steroidogenesis, including testosterone and estrogen suppression. Glerelin Injection is primarily indicated for the treatment of hormone-responsive conditions such as prostate cancer, endometriosis, uterine fibroids, and central precocious puberty. The depot formulation allows for sustained release and prolonged therapeutic effect, typically administered via intramuscular or subcutaneous injection every 3 months. Clinical use requires careful monitoring of hormone levels and symptomatology to assess efficacy and manage potential adverse effects, which may include hot flashes, injection site reactions, decreased libido, and bone mineral density reduction with long-term use. Contraindications include hypersensitivity to leuprolide or its components and pregnancy. Glerelin Injection should be used under specialist supervision with appropriate patient counseling regarding the expected hormonal changes and potential side effects. Dose adjustments may be necessary based on clinical response and tolerability.