All UFC 137 Drug Screens Come Back Clean

NSAC Executive Director Keith Kizer emailed Sherdog.com the testing results on Thursday afternoon. The extensive list of fighters who were tested and passed includes: B.J. Penn, Nick Diaz, Cheick Kongo, Roy Nelson, Scott Jorgensen, Hatsu Hioki, Donald Cerrone, Eliot Marshall, Brandon Vera, Chris Camozzi, Francis Carmont, Ramsey Nijem, Daniel Downes, Bart Palaszewski, Tyson Griffin, Dustin Jacoby and Clifford Starks.

Fighter urine samples are normally tested for both performance enhancing drugs and drugs of abuse.

Headlined by Penn and Diaz's welterweight collision, the event emanated from the Mandalay Bay Events Center in Las Vegas. The Oct. 29 show saw Diaz earn a shot at Georges St. Pierre's UFC title, as the Californian outpointed Penn in a bloody standup affair.