Watson, P., Judkins, C., Houghton, E., Russell, C., & Maughan, R. (2009). Urinary nandrolone metabolite detection after ingestion of a nandrolone precursor. Medicine & Science in Sports & Exercise, 41(4), 766-772.

This study quantified the excretion patterns of the diagnostic metabolites, 19-norandrosterone (19-NA), and 19-noretiocholanolone (19-NE) after ingestion of small doses of 19-nor-4-androstene-3,17-dione (19-norandrostenedione). Males (N = 11) and females (N = 9) followed an overnight fast. In the laboratory, an initial urine sample was collected. Ss then ingested 500 mL of water containing 5 g of creatine monohydrate and 1.0, 2.5, or 5.0 ng (micrograms) of 19-norandrostenedione. The volume of each urine void was measured, and an aliquot was taken. Samples were analyzed for the metabolites 19-NA and 19-NE by GCMS.

Baseline urinary 19-NA concentrations were ~2.0 ng/mL. Ingestion of the supplement resulted in peak mean urinary 19-NA concentrations of 0.68 ± 0.36, 1.56 ± 0.86, and 3.89 ± 3.11 ng/mL in the 1.0-, 2.5-, or 5.0-ng trials, respectively. Under current WADA regulations, ingestion of the 1.0-ng dose produced 0 positive doping tests, 5 Ss tested positive in the 2.5-ng trial, and 15 Ss (75%) had urinary 19-NA concentrations exceeding 2 ng/mL after ingesting creatine containing 5.0 ng of the steroid. The recovery of the ingested dose was highly variable between individuals, with values ranging from 11% to 84%.

Implication. Ingestion of trace amounts of 19-norandrostenedione (nandrolone precursor) can result in transient elevations of urinary 19-NA and 19-NE concentrations in some individuals. The addition of as little as 2.5 ng of 19-norandrostenedione to a supplement (0.00005% contamination) appears sufficient to result in a doping violation in some persons. Such a small amount would have no effect on a human's physiology or endocrine system. The different response patterns across individuals shows the test to be unfair because it locates only some individuals who have ingested the exogenous steroid precursor.

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