Jake Shields has been suspended until February due to a banned substance. Shields acknowledged the suspension in a statement sent to MMAjunkie.com from Authentic Sports Management.

“This was a mistake that I fully regret,” Shields’ statement read. “I have shared this issue with my family and the UFC, and I have apologized to them and now I also apologize to you, the fans. I promise this will never occur again in my fighting career.”

Shields defeated Ed Herman this past August in Denver. The bout was his first at middleweight since entering the UFC.

The suspension, which runs out in February of next year, was handed down by the Colorado Department of Regulatory Agencies’ Boxing Commission. The statement did not entail what banned substance Shields took.