Nutraferon LETROO Tablets

In postmenopausal women, estrogen is produced mainly by the aromatase enzyme in fat, muscle, and breast tissue. Letrozole blocks aromatase by over 95%, starving estrogen-receptor-positive breast cancer cells of the hormone they need to grow.

When taken for just 5 days early in the menstrual cycle, Letrozole temporarily lowers estrogen levels, prompting the pituitary gland to release a natural surge of Follicle-Stimulating Hormone (FSH) that matures and releases an egg—clearing from the body before implantation occurs.

In postmenopausal breast cancer, Letrozole is taken every day continuously. In fertility treatment, it is taken for only 5 days per cycle under ultrasound monitoring—and a negative pregnancy test must be confirmed before each cycle because Letrozole is strictly contraindicated once pregnancy is established.

No. Co-administration of Letrozole with Tamoxifen reduces plasma Letrozole concentrations by ~38%, and estrogen-containing therapies or phytoestrogens directly counteract its pharmacological action.

Common side effects include hot flashes, arthralgia (joint stiffness/pain), fatigue, and mild hypercholesterolemia. Because prolonged estrogen depletion reduces Bone Mineral Density (BMD) and increases osteoporosis/fracture risk, oncologists routinely monitor DEXA bone scans, serum cholesterol, and Vitamin D/calcium status.