The California Horse Racing Board released new threshold levels for the four most important anabolic steroids—testosterone, nandrolone, boldenone, and stanzolol.

Under the threshold levels, official urine test samples may contain one of the following drug substances, their metabolites, or analogs, in an amount that does not exceed the specified levels:

•  Stanozolol—one nanograms per milliliter

•  Nandrolone—one nanograms per milliliter for geldings, fillies, and mares; 45 nanograms for males other than geldings

•  Boldenone—15 nanograms per milliliter in males other than geldings

•  Testosterone—20 nanograms per milliliter in geldings and 55 nanograms per milliliter in fillies or mares. Testosterone at any level in males other than geldings is not a violation

Stanzolol is a pharmaceutical anabolic steroid.

Testosterone, nandrolone, and boldenone are naturally occurring anabolic steroids with normal threshold levels well established in horses. According to a CHRB release, the regulatory threshold levels for a violation include a wide safety margin.

Beginning May 31, the CHRB will regulate these steroids under Rule 1844, which is the same rule that regulates other drugs, such as clenbuterol, with specified threshold levels.

California horsemen will not see any changes until July 1, when in-dept testing of routine samples for anabolic steroids will begins at the University of California-Davis’s Ken Maddy Laboratory.