No evidence found of fake or counterfeit PrEP in any samples examined in new research by HIV organisations PrEPster and Terrence Higgins Trust. Reassurance has come for the thousands currently sourcing HIV prevention pill PrEP (pre-exposure prophylaxis) online as a new study commissioned by HIV organisations Terrence Higgins Trust and PrEPster finds that samples from the six leading online suppliers are the real deal.