Chael Sonnen announces his retirement from MMA after failing drug test

Chael Sonnen announced his retirement as an MMA fighter Wednesday night, ending his 17-year career a day after he was pulled from UFC 175 after failing a drug test. 

"I am officially done, I will not step foot in that Octagon again," Sonnen, 37, said. 

Fox Sports' Marc Raimondi has more on the failed drug test, and Sonnen's announcement:

At the top of ["UFC Tonight"], 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.

Sonnen retires with a 29-14-1 UFC record, and a reputation as one of the most divisive and popular fighters in UFC history. 

Sonnen thanked many, but one person in particular:

I want to thank the single most important opponent I ever had. I couldn't have gotten to where I am without this dance partner and that is, of course, Anderson Silva. I thank you for the opportunity and the memories.