Clopidogrel hydrogen sulfate is an antiplatelet agent administered, alone or in combination with acetyl salicylic acid, approved in the prevention of cardiovascular events based on large-scale clinical trials. The new salt formulations clopidogrel where approved based on pharmacokinetic measurements of the inactive prodrug on few healthy volunteers, without any other medication. Clopidogrel hydrogen sulfate has a wide variability in platelet response and the pharmacokinetic of the active metabolite is not dose-linear. Ideally, new clopidogrel salts should be tested for therapeutic equivalence in the target patient population. Should this not be feasible, consistent bioequivalence data should be obtained for the active metabolite, using a properly validated and standardized test method.