How do hormone signals help start puberty?

Puberty is the period when the body develops toward sexual maturity. Changes unfold over years, with timing and pace that vary among people. A central part is a signaling connection between the brain, the pituitary gland and the gonads, meaning ovaries or testes. The signals help coordinate changes in several tissues rather than making every part develop at once.

A brain region called the hypothalamus releases pulses of gonadotropin-releasing hormone, shortened to GnRH. This acts on the pituitary gland, which releases luteinizing hormone and follicle-stimulating hormone, called LH and FSH. These travel to the ovaries or testes. Each step changes the activity of another part of the system.

The gonads produce hormones, including estrogens and testosterone, and develop their reproductive functions. Hormones affect many tissues, contributing to changes such as breast development, voice change and changes in body composition. People of all sexes make both estrogens and testosterone in differing patterns. Additional signals, including adrenal hormones, contribute to changes such as body hair.

Gonadal hormones also feed information back to the hypothalamus and pituitary, helping regulate further signaling. In a simplified negative-feedback relationship, an increased downstream signal can reduce the upstream drive; this is regulation, not a claim that puberty reverses. Actual hormone patterns are more complex than one fixed loop. The pathway explains communication among organs without prescribing a schedule or a single way an individual body must develop.