ultra-long GnRH agonists + letrozole

Ultra-long GnRH agonists + letrozole is a **combination regimen** used primarily in assisted reproduction (IVF/ICSI), especially for women with endometriosis, adenomyosis, or recurrent implantation failure. The protocol combines **ultra-long-acting gonadotropin-releasing hormone agonists (such as leuprolide acetate or triptorelin)** with **letrozole**, a third-generation aromatase inhibitor. The GnRH agonists act by downregulating the pituitary–gonadal axis, resulting in suppression of endogenous gonadotropin secretion and ovarian function. Letrozole decreases estrogen synthesis by inhibiting aromatase, reducing estrogen-dependent disease activity and possibly improving endometrial receptivity. This combination aims to enhance IVF outcomes by efficiently suppressing estrogen biosynthesis both at the central (pituitary/ovarian) and peripheral (endometriotic lesions) levels. It is used as part of ovulation induction or pretreatment in specific populations, including women with endometriosis, adenomyosis, or recurrent implantation failure[3][4][6].

Other names

ultra-long GnRH agonist protocol + letrozole