19-NORANDROSTENEDIONE AND 19-NORANDROSTENEDIOL NOT FOUND TO BE PRECURSORS OF NANDROLONE
Dehennin, L., Bonnaire, Y., & Plou, P. (2002). Human nutritional supplements in the horse: comparative effects of 19-norandrostenedione and 19-norandrostenediol on the 19-norsteroid profile and consequences for doping control. Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences, 766, 257-263.
"The dietary supplements 19-norandrostenedione and 19-norandrostenediol are potential metabolic precursors of nandrolone. They are considered by law in the United States as prohormones without proven therapeutic, curative, or diagnostic properties, and therefore available as over-the-counter drugs. Oral dosages of 0.1-1 mg/kg body weight were readily absorbed in the equine intestinal tract and thereby led to urinary excretion of drastically increased 5alpha-estrane-3beta,17alpha-diol conjugates, which are known to be final metabolites of nandrolone. The actual rules for detection of illicit nandrolone administration to the horse have been found applicable for the detection of surreptitious oral 19-norandrostenedione and 19-norandrostenediol supplementation. Secondary markers of these administrations were high-level excretions of conjugated nandrolone, epinandrolone, 19-noretiocholanolone and 19-norepiandrosterone. No significant increase of circulating, biologically active nandrolone could be firmly evidenced, and it is therefore unclear to what extent continuous long-term administrations may have anabolic action".
Implication. This animal study found that the detection of nandrolone metabolites is not associated with elevated levels of nandrolone. The assumption that the existence of the metabolites is the result of nandrolone use is unsupported.