KHK-IN-1 (KHK-IN-8) is a selective and cell membrane permeable inhibitor of ketohexokinase (KHK, IC50=12 nM; F=34%). KHK-IN-1 inhibits F1P production in HepG2 cell lysates with IC50 of 400 nM. KHK-IN-1 has potential for the study of obesity and diabetes.