In vitro inhibition of monoamine transport by amphetamine-like pre-workout supplement ingredients

values between -66.8% and -135%. For hSERT 50% inhibition was observed at concentrations ranging from 2.6 µM to 131 µM, with maximal effect between 85.3% and -64.8%. These findings indicate a potential for sympathetic activation and behavioral rewarding and reinforcing effects. Notably, the in vitro potency and efficacy of several PEAs and AAs were comparable to those of the well-known illicit stimulants amphetamine and cocaine. Together, these findings highlight the urgent need to further characterize pharmacokinetic and pharmacodynamic properties of these pre-workout supplement ingredients to support robust risk assessment and informed regulatory decision-making regarding the safety of pre-workout supplement ingredients.