Aromatase (CYP19A1) is a monooxygenase from the family of cytochrome P450 that plays role in the androgens to estrogens conversion. Aromatase inhibitors prohibit the aromatase enzyme function. This study reviewed the different usages of aromatase inhibitors in the male gender. In this review study, all articles related to the effect of aromatase inhibitors in males were evaluated through databases such as PubMed, Web of Science, Scopus, Science Direct, Google Scholar, and Cochrane library using the keywords “aromatase inhibitors”, “infertility”, “bone metabolism”, “Breast cancer”, “obesity”, “men” and “male”. Estrogen excess in males shows a correlation with premature closure of the epiphyses. Aromatase inhibitors reduce estrogen by preventing the testosterone to estrogen conversion and have thus been used in patients with short stature or with a delay of puberty. The breast cancer cells show aromatase activity, a probable source of local estrogen for the tumor cells. The inhibition of aromatase suppresses the amounts of serum estrogen and reduces cancer cell proliferation mediated by estrogen in hormone receptor-positive breast cancer. Aromatase inhibitors have also been used in late-onset hypogonadism by lowering the levels of estrogen which is correlated with luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and testosterone increase. In obese males, an augmented androgen-to-estrogen conversion happens in the adipose tissue, resulting in raised estrogen levels. Aromatase inhibitors by reducing this conversion lead to a reduction of estrogen and elevation of testosterone and FSH in males with obesity-associated hypogonadotropic hypogonadism. Furthermore, aromatase inhibitor therapy reduced the breast size in males with gynecomastia. They may affect bone metabolism.
