Stephan Bonnar and Dave Herman both tested positive for banned substances following their recent fights at UFC 153: Silva vs. Bonnar, according to MMAjunkie.com. The two were the lone fighters to fail the post-fight drug tests given.
Bonnar, who announced his retirement earlier this week following his loss to Anderson Silva, tested positive for Drostanolone, an anabolic steroid. Herman, who was defeated by Antonio Rodrigo Nogueira, had marijuana metabolites in his system.
For both Bonnar (15-8) and Herman (21-5) this was a second failed drug test. “The American Psycho” also tested positive for an anabolic steroid following a loss to Forrest Griffin, while Herman failed a pre-fight test before a scheduled bout with Mike Russow.