The suppression of gonadotropin-releasing hormone (GnRH) release from the hypothalamus is removed during development, typically between ages 11 and 15, allowing GnRH to activate cells in the anterior pituitary.

“So whether or not we're talking about onset of puberty at this age or that age and whether or not biologically-related male or non-biologically-related male scents around, et cetera, the thing I want everyone to know is that at some point during development, typically nowadays between the ages of 11 and 15 or so-- again, there's variability there. The suppression of gonadotropin-releasing hormone released from the hypothalamus is removed, and then gonadotropin-releasing hormone can activate cells within the pituitary.”