Letrozole: Aromatase Inhibitor

Letrozole is a highly potent, non-steroidal Aromatase Inhibitor (AI). Its primary medical use is in the treatment of hormone-receptor-positive breast cancer in postmenopausal women. In the context of performance enhancement and hormone therapy, it is used to control estrogen levels. When using anabolic steroids that can convert (aromatize) into estrogen, such as testosterone, Letrozole works by blocking the aromatase enzyme, thereby preventing this conversion. This is crucial for preventing estrogenic side effects like gynecomastia (male breast tissue development), water retention, and high blood pressure. Maintaining a balanced estrogen-to-androgen ratio is critical for health. While excessively high estrogen is problematic, crashing estrogen levels too low with an overly aggressive AI regimen can be equally detrimental, leading to joint pain, low libido, and poor cholesterol profiles. Therefore, the use of powerful AIs like Letrozole requires careful blood work monitoring to ensure hormonal balance, a key factor in biological age.