Carbon isotope ratios of nandrolone, boldenone, and testosterone preparations seized in Norway compared to those of endogenously produced steroids in a Nordic reference population

Drug Test Anal. Nov-Dec 2014;6(11-12):1163-9. doi: 10.1002/dta.1745. Epub 2014 Nov 11.


Determining the origin of anabolic androgenic steroids (AAS) that also are produced endogenously in the human body is a major issue in doping control. In some cases, the presence of nandrolone and boldenone metabolites might result from endogenous production. The GC-C-IRMS technique (gas chromatography-combustion-isotope ratio mass spectrometry) enables the carbon isotopic ratio (CIR) to be measured to determine the origin of these metabolites. The aim of this study was to use GC-C-IRMS to determine the δ(13) CVPDB values of seized boldenone and nandrolone preparations to decide if the steroids themselves were depleted in (13) C, compared to what is normally seen in endogenously produced steroids. In addition, several testosterone preparations were analyzed. A total of 69 seized preparations were analyzed. The nandrolone preparations showed δ(13) CVPDB values in the range of -31.5 ‰ to -26.7 ‰. The boldenone preparations showed δ(13) CVPDB values in the range of -32.0 ‰ to -27.8 ‰, and for comparison the testosterone preparations showed δ(13) CVPDB values of -31.0 ‰ to -24.2 ‰. The results showed that the values measured in the nandrolone and boldenone preparations were in the same range as those measured in the testosterone preparations. The study also included measurements of CIR of endogenously produced steroids in a Norwegian/Danish reference population. The δ(13) CVPDB values measured for the endogenous steroids in this population were in the range of -21.7 to -26.8. In general, most of the preparations investigated in this study show (13) C-depleted delta values compared to endogenously produced steroids reflecting a northern European diet.

Keywords: IRMS-analysis; doping analysis; reference population; steroid preparations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anabolic Agents / analysis*
  • Carbon Isotopes / analysis
  • Denmark
  • Esters / analysis
  • Esters / urine
  • Female
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Male
  • Nandrolone / analysis*
  • Norway
  • Reference Standards
  • Solutions
  • Testosterone / analogs & derivatives*
  • Testosterone / analysis*
  • Young Adult


  • Anabolic Agents
  • Carbon Isotopes
  • Esters
  • Solutions
  • Testosterone
  • boldenone
  • Nandrolone