Thevis M, Schrader Y, Thomas A, Sigmund G, Geyer H, Schanzer W. Analysis of confiscated black market drugs using chromatographic and mass spectrometric approaches. J Anal Toxicol. 2008;32(3):232-240.

In the context of house searches in Germany, numerous drugs were confiscated and subjected to chemical analysis, including anabolic agents such as various anabolic-androgenic steroids (stanozolol, testosterone derivatives, trenbolone esters, etc.) and clenbuterol, as well as agents with anti-estrogenic activity (tamoxifen, clomiphene), drugs stimulating virility (sildenafil, tadalafil), and unlabeled plastic bags. Liquid chromatography-tandem mass spectrometry, gas chromatography-mass spectrometry with nitrogen-phosphorus specific detection, gel electrophoresis, and immunological tests were employed to test for the effective content of 70 products. In 18 cases (25.7%), the declared ingredients differed from the actual content, in particular concerning anabolic-androgenic steroids. Nandrolone and trenbolone esters, for instance, were frequently substituted or complemented by various testosterone derivatives, and several testosterone depot formulations originally composed of four different esters were found to contain fewer or wrong components. Except for those drugs supposedly originating from so-called underground labs, fake packings were hardly or not distinguishable from original boxes by visual inspection.