Adrenocorticotropic hormone, commonly called ACTH, is a protein hormone naturally produced in the horse. The function of ACTH is to stimulate and also regulate levels of the steroid hormone cortisol. Commercially available ACTH is a synthetically produced peptide hormone which is high similar in structure to ACTH produced naturally. As a prohibited substance in horseracing the use of synthetic ACTH is most commonly monitored and prosecuted by the increase which is observed the level of naturally produced hydrocortisone. As the hydrocortisone level increases beyond the international threshold, this is prosecuted as a prohibited substance offence. 

There are also other approaches to detect the use of synthetic ACTH. One of these is based on the fact that synthetic ACTH corresponds to the structure of human ACTH. It can therefore be detected in the horse as the structure of this protein is somewhat different to naturally produced ACTH in the horse.  The NHA Laboratory is one of a few racing laboratories which have been active in the research of new approaches for the detection for synthetic administered ACTH in the race horse. During recent years ACTH administration trials were conducted on horses as part of such research at our Laboratory.  This research was formally presented at an international conference for horse racing chemists and veterinarians.

It must be noted that at least one web based sales company is selling a product which purport to contain the biochemically active molecule of ACTH. Several racing laboratories have already analysed this preparation. Such analysis however indicated that the active peptide ACTH is either not contained or is only contained in a very low concentration, certainly too low to effect the horse.