What is the Origin of Letrozole for Fertility?

Letrozole was originally developed and approved as an endocrine therapy for postmenopausal women with breast cancer, acting to suppress estrogen production. Its application for fertility treatment arose from the understanding of its pharmacological action on the hypothalamic-pituitary-gonadal (HPG) axis. The use of the drug for this purpose is an example of drug repurposing based on a deep understanding of endocrinological feedback mechanisms.

What is the Mechanism of Letrozole for Fertility?

Letrozole's mechanism involves the potent, reversible inhibition of the aromatase enzyme, which is responsible for converting androgens into estrogens, particularly in the ovaries and peripheral tissues. By transiently lowering circulating estrogen levels, Letrozole reduces the negative feedback signal to the hypothalamus and pituitary. This reduced inhibition causes a compensatory increase in the secretion of Follicle-Stimulating Hormone (FSH), which then drives the development and maturation of a dominant ovarian follicle, ultimately leading to successful ovulation.

Letrozole for Fertility ∞ Area

Letrozole for Fertility

Meaning

Letrozole for Fertility refers to the off-label clinical use of the aromatase inhibitor drug Letrozole as an oral agent to induce ovulation in women experiencing anovulation, most commonly those with Polycystic Ovary Syndrome (PCOS). This treatment is a preferred first-line therapy for ovulation induction due to its favorable side effect profile and reduced risk of multiple gestations compared to older agents. The clinical objective is to restore the natural ovulatory cycle by transiently manipulating the estrogen feedback loop to the pituitary gland. It offers a targeted, non-invasive approach to managing certain types of female infertility.