FSH receptor-binding inhibitor fragment (bi-10) is a potent antagonist that inhibits the binding of follicle-stimulating hormone (FSH) to its receptor (FSHR), modifying FSH activity at the receptor level. It suppresses ovulation and induces follicular atresia in mice. Furthermore, this compound holds potential for curbing ovarian cancer carcinogenesis by reducing the overexpression of FSHR and estrogen receptor beta (ERβ) in the ovaries [1].