Group data (mean ± SEM) showing (A) GnRH and (B) kisspeptin release levels in prepubertal (16.4 ± 1.0 mo of age, n = 9), early pubertal (30.5 ± 1.5 mo of age, n = 5), and midpubertal (36.5 ± 1.3 mo of age, n = 5) stage males. Both GnRH and kisspeptin levels in all pubertal stages were significantly greater (P < 0.001 for all) than those in prepubertal monkeys. aaaP < 0.001 vs prepubertal stage.