The black market for pharmaceuticals has grown in recent years, largely due to the easy trade of products over the Internet. This trend poses a potential risk to consumers’ health, as it is not always possible to identify the origin of the products, which can be counterfeit. This study was designed to identify capsule components by full-scan mass spectrometry analyses coupled to liquid chromatography based on a single injection of the capsule material previously solubilized in methanol. The simultaneous analysis of other compounds that could be used as adulterants was performed in a fast chromatographic run based in a multi-step gradient, only 11minutes were necessary to evaluated all the substance without isomeric co-elution. The mass spectrometer was set to operate switching the ionization mode: positive and negative, for FULL HRMS and all-ion fragmentation acquisition, simultaneously. By WhatsApp groups, the GloboNews reporting team purchased a box of amfepramone capsules from dealers of counterfeit controlled drugs. The contents of the capsules analyzed did not contain any traces of amfepramone or any anorectic agents. The result of this study suggest the need for greater and more effective control by competent authorities to avoid black market medicines and to combat drug smuggling and counterfeiting.