Induction of insulin secretion by kisspeptin is observed in mouse, pig, rat, and human islets in vitro and in rats, mice and monkeys in vivo, but its mechanism is not fully clear. The present study was designed to investigate the role of KP-10 on insulin secretion in adult healthy and obese men with insulin resistance. The aim of selection of obese persons for the present study was to investigate the effect of acute KP-10 administration in a metabolically challenged condition where the pancreatic beta cells are already highly activated. The long-term objective of this study was to understand the physiological role of kisspeptin signalling in the regulation of insulin secretion in human health and disease.