In the context of the fight against illegal and falsified medicines, the illegal adulteration of dietary supplements and other products,
like cosmetics, medical devices, and food products, with pharmaceutical ingredients is an underestimated phenomenon and
is generally indicated as medicines in disguise. However, from the point of view of protecting public health, medicines in disguise
represent a serious risk for consumers' health due to adverse effects and possible interactions with therapies already used by a
patient to treat a (chronic) medical condition, and who is unaware he is taking a medicine. With an overview of a series of cases
reported in the literature, this paper intends to raise awareness about this issue, emphasizing the extent of products that may be
concerned and the range of adulterants that may be encountered. Equally important are the analytical techniques, suitable for
the detection and identification of adulterants and the analysis of medicines in disguise. Laboratories have a whole plethora of
techniques at their disposal; however, there is also a need for simple portable screening techniques to support customs officers
and inspectors in their choice of identifying products as suspicious and their decision to seize.