Amin A, Frampton J, Liu Z, et al. - In this study, the impacts of L‐phenylalanine on gastroenteropancreatic hormone release, glucose levels, subjective appetite, and energy intake were explored in humans, and to ascertain whether these impacts were stereoisomer‐specific by comparing them with D‐phenylalanine. Researchers carried out a dose‐finding, non‐randomized, unblinded, crossover study during October–December 2017 at the NIHR Imperial Clinical Research Facility in five participants, in which the tolerability of escalating doses of oral L‐phenylalanine was assessed (0, 3, 6, and 10 g). This study’s findings demonstrate that the ingestion of L‐phenylalanine, but not D‐phenylalanine, increases insulin, glucagon, and glucose‐dependent insulinotropic polypeptide concentrations without appearing to have a marked effect on appetite.