Outcomes of anastrozole in oligozoospermic hypoandrogenic subfertile men

Subfertile hypoandrogenic oligozoospermic men significantly improved their sperm parameters after anastrozole treatment. The increase in the total motile count was correlated with the change in the testosterone/ estradiol ratio.

Volume 107, Issue 3, Pages 589–594


Ohad Shoshany, M.D., Nikita Abhyankar, M.D., Naem Mufarreh, M.S., Garvey Daniel, M.D., Craig Niederberger, M.D.



To determine whether the change in sperm parameters in subfertile hypoandrogenic men treated with anastrozole is correlated to the magnitude of increase in testosterone (T) to estrogen ratio in men responding to treatment.


Retrospective study.


Male fertility clinic.


The study group consisted of 86 subfertile hypoandrogenic men with low T/estradiol (E2) ratio (n = 78) or a prior aversive reaction to clomiphene citrate (n = 8).


All patients were treated with 1 mg anastrozole daily, administered orally.

Main Outcome Measure(s)

Hormone analysis and semen analysis before and after treatment were performed. Hormone analysis included measurements of total T, E2, sex-hormone binding globulin, albumin, FSH, and LH, and bioavailable T was calculated. Total motile sperm count was calculated from the semen analysis.


In all, 95.3% of patients had an increased serum T and decreased serum E2 after treatment with anastrozole. Sperm concentration and total motile counts improved in 18 of 21 subfertile hypoandrogenic oligozoospermic men treated with anastrozole. In these men the magnitude of total motile count increase was significantly correlated with the change in the T/E2 ratio. No improvement was seen in semen parameters of men with azoospermia, cryptozoospermia, or normozoospermia at presentation.


Approximately 95% of men with hypoandrogenism responded with improved endocrine parameters, and a subset of oligozoospermic men (approximately 25% of all patients) displayed significantly improved sperm parameters. In that subset, increase in sperm parameters was correlated with the change in the T/E2 ratio, which argues for a physiologic effect of treatment.

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Go to the profile of T. Mike Hsieh
almost 6 years ago
this is another article showing the benefit of an off-label use of anastrozole to improve semen parameters. it's known that aromatization of T occurs in the adipose tissue. since the ideal dosing for aromatase inhibitor is unknown, my question for the authors is whether BMI or %body fat correlated with hormonal and spermatogenesis response on therapy and whether they considered titrating anastrozole dosing base on hormonal response.