Fezol 2.5 mg is a medication manufactured by ACME Laboratories Ltd., containing the active ingredient Letrozole, a nonsteroidal aromatase inhibitor. It is primarily used in the treatment of hormone receptor-positive breast cancer in postmenopausal women. Letrozole works by inhibiting the aromatase enzyme, which is responsible for converting androgens into estrogens. By reducing estrogen levels, Letrozole helps to slow or stop the growth of estrogen-dependent breast cancer cells. Fezol 2.5 mg is indicated