Human nutritional supplements in the horse: comparative effects of 19-norandrostenedione and 19-norandrostenediol on the 19-norsteroid profile and consequences for doping control.

This research article investigates the effects of human supplements, 19-norandrostenedione and 19-norandrostenediol on horses. It explores these substances’ potential as precursors to nandrolone, a drug monitored in doping control, and recognises that the current rules fit for detecting illicit nandrolone use also apply to these supplements. However, the extent of their anabolic action through long-term use is undetermined.

Background of the Research

• The two supplements under study, 19-norandrostenedione and 19-norandrostenedione, are considered prohormones and are available over-the-counter in the US due to their lack of definitive therapeutic, curative, or diagnostic properties.
• They are thought to be potential precursors of nandrolone, a pharmacologically active steroid, the use of which is monitored in anti-doping controls.

Methodology and Findings

• The researchers administered oral dosages of the supplements to horses in quantities of 0.1-1 mg per kg body weight.
• These substances were easily absorbed in the equine intestinal tract and led to increased urinary excretion of 5alpha-estrane-3beta,17alpha-diol conjugates, which are end metabolites of nandrolone.
• This means the supplements could potentially alter a horse’s natural nandrolone balance, and their use could be hidden by presenting this off-balance state as natural.
• The current regulations for detecting illegal nandrolone use in horse doping controls were found to apply to the detection of these supplements as well.
• Apart from that, administrations of these supplements caused high-level excretions of conjugated nandrolone, epinandrolone, 19-noretiocholanolone, and 19-norepiandrosterone, which serve as secondary markers of these supplements’ administrations.

Implications and Further research

• No significant increase in circulating, biologically active nandrolone was recorded, leaving it unclear whether continued long-term usage of these supplements could have anabolic actions.
• More research is needed to clarify the impact of these supplement’s long-term applications on the equine’s physical performance.