6-oxo is a potent irreversible aromatase inhibitor that inhibits estrogen biosynthesis. It does this by permanently binding and inactivating aromatase in adipose and peripheral tissue. Aromatase is one of the most important factors that affect testosterone levels and the ratio between testosterone to estrogen. Aromatase is responsible for the conversion of testosterone to estradiol (and ultimately estrogen), further depleting free testosterone levels and increasing estrogen levels.

It must be noted that estrogen is very important in male sexual function and is essential for modulating libido, erectile function and spermatogenesis. However, when estrogen levels get too high in men this can cause female like symptoms such as breast growth, low muscular development and even mood swings. Aromatase inhibitors have been used as a tool to increase testosterone levels in men.

By blocking aromatase, this causes the body to decrease levels of estradiol, which in turn increases luteinizing hormone and consequently, testosterone.


  • Strongest aromatase inhibitor on the market
  • Increase lean muscle mass
  • Reduce conversion of testosterone to estradiol
  • Supports muscle retention
  • Increase testosterone : estrogen ratio