In the traditional tests for antipsychotic effect, eg antagonism of stereotypic behaviour induced by dopamine agonists, the chemical groups of antipsychotics mentioned reveal equal but dosage-dependent activity. However, the antistereotypic effects of phenothiazines, butyrophenones, diphenylbutylpiperidines, and benzamides is strongly counteracted by the anticholinergic drug scopolamine, while the antistereotypic effect of thioxanthenes, eg flupentixol is not, or only very slightly, influenced by concomitant treatment with anticholinergics.
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.