Aromasin is suicidal aromatase inhibitor also known as exemestane. Exemestane takes up to 7 days to reach maximal inhibition of aromatase1. Maximal suppression with exemestane only reaches about 60-70% for estradiol and estrone1 though another paper shows near 100% inhibition of estrone production2. Exemestane has been associated with androgenic and progestational side effects, which bring its usefulness for post-cycle therapy into question. Not many athletes use exemestane as an aromatase inhibitor. A dose of 25 mg resulted in an increase in testosterone levels of 60% in healthy young males3. As stated, it is probably not the best choice for post-cycle therapy but is used as on-cycle therapy to keep estrogen levels low. As with other aromatase inhibitors, exemestane will alter lipid profiles and may result in compensatory upregulation of sensitivity to estrogen especially when using higher doses.
1. Buzdar AU: Pharmacology and pharmacokinetics of the newer generation aromatase inhibitors. Clin Cancer Res. Jan;9(1 Pt 2):468S-72S, 2003
2. Lonning PE: Exemestane: a review of its clinical efficacy and safety. Breast. Jun;10(3):198-208, 2001
3. Mauras N, Lima J, Patel D, Rini A, di Salle E, Kwok A, Lippe B: Pharmacokinetics and dose finding of a potent aromatase inhibitor, aromasin (exemestane), in young males. J Clin Endocrinol Metab. Dec;88(12):5951-6, 2003