Human enteropeptidase-IN-1 (compound 6b) is a highly potent, orally active and low systemic exposure enteropeptidase inhibitor. Human enteropeptidase-IN-1 boosts the increase in fecal protein output, and exhibits potent body weight loss in diet-induced obese (DIO) rat model. Human enteropeptidase-IN-1 can be used for anti-obesity research.