Position on the Use of Anabolic Steroids

Definition and Mode of Action
Anabolic steroids are a group of naturally occurring and/or synthetic hormones including androgens (testosterone and its derivatives), estrogen and progestins. The action of these substances is to increase protein synthesis, particularly in skeletal muscle. Anabolic steroids have specific indications in the therapeutic treatment of medical conditions of horses.

Indications for Use
Indications for use: Anabolic steroids are primarily effective when the objective is to improve appetite, repair tissue, promote weight gain and accelerate recovery from disease. In horses, anabolic steroids may stimulate appetite and increase muscle mass, particularly when there has been marked tissue breakdown associated with disease, prolonged anorexia, stress, or surgery.

Potential side effects of anabolic therapy: Anabolic steroids may cause aggressive or male-like behavior in mares or geldings. Of greater concern are the potentially adverse effects of anabolic steroids on the reproductive function of both mares and stallions. Although these effects are not thought to be permanent, consideration must be given to this possibility.

Additionally, anabolic steroids, like other drugs, should only be prescribed where a doctor/client/patient relationship exists and only for the therapeutic treatment of specific medical conditions. In adherence with its medication policies related to competition horses, the AAEP recommends that practitioners abide by the rules governing the jurisdiction or competition in which they practice (for example: HISA considers anabolic steroids banned substances). Veterinarians must exercise extreme caution in prescribing anabolic steroids to prevent their acquisition for human use.

Revised by AAEP board of directors in 2025.