Introduction: Quantities of various anabolic/androgenic steroids have been found in dietary supplements without their presence being disclosed on the label. The aim of this study was to quantify 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).
Methods: Eleven males and nine females entered the laboratory in the morning after an overnight fast. An initial urine sample was collected, and volunteers then ingested 500 mL of water containing 5 g of creatine monohydrate and 1.0, 2.5, or 5.0 microg 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.
Results: Baseline urinary 19-NA concentrations were 0.19 +/- 0.14 ng x 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-microg trials, respectively. Under current WADA regulations, ingestion of the 1.0-microg dose produced 0 positive doping tests, 5 subjects (20%) tested positive in the 2.5-microg trial, and 15 subjects (75%) had urinary 19-NA concentrations exceeding 2 ng x mL after ingesting creatine containing 5.0 microg of the steroid. The recovery of the ingested dose was highly variable between individuals, with values ranging from 11% to 84% (mean +/- SD = 47% +/- 18%).
Conclusions: Ingestion of trace amounts of 19-norandrostenedione can result in transient elevations of urinary 19-NA and 19-NE concentrations. The addition of as little as 2.5 microg of 19-norandrostenedione to a supplement (0.00005% contamination) appears sufficient to result in a doping violation in some individuals.