New York City’s largest cop union is suing Police Commissioner Edward Caban and Mayor Adams for implementing a new “zero tolerance” policy on NYPD officers using steroids or other performance-enhancing drugs, the Daily News has learned.

In a lawsuit filed in Manhattan Supreme Court on Friday, lawyers for the Police Benevolent Association alleged the previously undisclosed policy flies in the face of a legal agreement the union entered into with the city in 2011.

The 2011 contract prohibited officers from ingesting or possessing any anabolic steroid or other forms of human growth hormones without a medical prescription. However, the old standard didn’t require officers to run any such prescription by their NYPD district surgeon before starting to use it.

The new protocol — which was enacted on Dec. 26, 2023, and described in an internal memo reviewed by The News as a “zero tolerance drug policy” — beefs up the old rule by affirming that officers must “immediately notify their district surgeon” of any steroid prescription they receive and provide “all supporting medical documentation” to the surgeon backing up the need for the drug.