Unavailability of PrEP in different countries, or upcoming availability, may impact studies. In our case, we are about to begin a study on injectable PrEP, to be compared with oral PrEP. Participation in this study may be seen as an opportunity to access to PrEP (a case of therapeutical misconception), so it will be very important to highlight in the informed consent process that the participant may be randomized to active injectable PrEP, whose efficacy is unknown. Even then, a person who is not able to access PrEP, e.g. who has no money to buy “wild PrEP”, may tend to join the study – and probably will quit it as soon as oral PrEP is available in the public health system.