KISS1 and osteoporosis: Both kisspeptin and its receptor are essential for reproduction in men and women.4It was recently demonstrated in rodents that its administration promotes thein vitrodifferentiation of osteoblasts through the expression of its receptor (KISS1R or GPR54).4, 5Thus, kisspeptin may have direct beneficial effects on skeletal homeostasis, independently of its role in the release of sex steroids.5However, there are few data on its expression and function, as well as its receptor, in bone, especially in osteoporosis related to hypoestrogenism.