Heavy consumption of the essential amino acid lysine (as indicated in the treatment of cold sores) has allegedly shown false positives in some and was cited by American shotputter C. J. Hunter as the reason for his positive test, though in 2004 he admitted to a federal grand jury that he had injected nandrolone.  A possible cause of incorrect urine test results is the presence of metabolites from other AAS, though modern urinalysis can usually determine the exact AAS used by analyzing the ratio of the two remaining nandrolone metabolites. As a result of the numerous overturned verdicts, the testing procedure was reviewed by UK Sport . On October 5, 2007, three-time Olympic gold medalist for track and field Marion Jones admitted to use of the drug, and was sentenced to six months in jail for lying to a federal grand jury in 2000. 
To strengthen the anabolic properties of testosterone, more than 100 synthetic steroid derivatives have been described for human purposes. The anabolic effect promotes protein synthesis, muscle growth and erythropoiesis. In clinical practice, substances with anabolic effect are needed to overcome various catabolic states. However, none of these compounds are devoid of androgenicity. Androgenic and anabolic properties of anabolic steroids cannot be totally separated. Therefore, it is more appropriate to use the term anabolic androgenic steroids (AAS).
Travellers may carry narcotics that have been prescribed by a doctor, while travelling for a period of up to 30 days within the states of the Schengen area, if they are in possession of a certificate pursuant to Article 75 of the Schengen Agreement, that has been completed by the attending doctor and that has been certified prior to the journey by the highest regional health authority or by a competent body acting on behalf of that health authority. You can find additional relevant information and the form mentioned (downloadable PDF file) on the website of the Federal Institute of Drugs and Medical Devices ( Bundesinstitut für Arzneimittel und Medizinprodukte - BfArM ).