http://msn.foxsports.com/ufc/story/c...ighting-061114

Chael Sonnen's recent failed drug test hasn't just led to him being pulled from UFC 175. It will also mark the end of his MMA career.

Sonnen announced his retirement from competition Wednesday on UFC Tonight, one day after news came out that he had tested positive for banned substances and would likely not be able to fight Vitor Belfort on July 6 in Las Vegas. Sonnen has competed in MMA for 17 years, including the last five with the UFC.

At the top of the show, Sonnen further explained why he was taking human chorionic gonadotropin, anastrozole and clomiphene. The latter two are anti-estrogen medications typically given to women. Sonnen, 37, has hypogonadism, an affliction that affects the output of testosterone. He was on testosterone replacement therapy (TRT) before it was banned by the Nevada Athletic Commission in February. Once he came off that, Sonnen said doctors prescribed him anastrozole and clomiphene with the hope of stimulating natural testosterone production.

In some ways, it worked. Sonnen said he had fertility issues previously and now his wife Brittany is pregnant with their first child. He said he was putting his health and family first and would do the same thing again if given the choice.