Estradiol cypionate（Cat No.:A000607）is a long-acting estrogen ester with the molecular formula C26H36O3, used primarily in hormone replacement therapy and for managing menopausal symptoms, ovarian failure, and certain cancers. It is a synthetic derivative of 17β-estradiol, formulated as an intramuscular injection to provide sustained estrogenic effects. Once administered, it is hydrolyzed to active estradiol, which binds to estrogen receptors, regulating gene expression and maintaining secondary sexual characteristics. Estradiol cypionate is also used in feminizing hormone therapy for transgender women. Common side effects include breast tenderness, nausea, and fluid retention, requiring medical supervision.