Understanding puberty as a longer, hormone-driven process that begins earlier in girls

Clinicians highlight that puberty in girls is a broader, longer process starting at a younger age, with implications for health, socialisation, and education, amid rising evidence of earlier development linked to environmental and lifestyle factors.

Puberty in girls is often reduced to the arrival of periods and the need for bras, but clinicians say the process is broader, longer and, for many families, starting younger than expected. In a discussion highlighted by TheNourishedChild.com, Melisa Holmes, a board-certified obstetrician-gynecologist and co-founder of Girlology, described puberty as a hormone-driven development that unfolds over 5 to 7 years, beginning in most girls with breast buds and continuing well after the first period as growth and brain development carry on. The conversation reflects a wider push among paediatric specialists to help parents understand puberty as a gradual transition rather than a single milestone.

That urgency is partly driven by evidence that pubertal timing is shifting. Research cited by the Endocrine Society and the National Institute of Environmental Health Sciences found that girls with higher body fat tend to begin menstruating earlier, even though breast maturation may progress more slowly. The studies link greater total body fat with higher levels of reproductive hormones, including follicle-stimulating hormone, inhibin B and testosterone. Holmes also pointed to other suspected contributors to earlier puberty, including less nutritious diets, lower physical activity, chronic stress and exposure to endocrine-disrupting chemicals, which can interfere with hormone signalling and have been found in products ranging from plastics to pesticides.

Earlier development can carry social and emotional costs as well as physical ones. National Geographic has reported that girls who mature sooner may face more body-image pressure, earlier sexualisation and greater exposure to risky peer dynamics. Holmes also warned against a form of adultification that can affect Black girls disproportionately, where early physical development leads others to treat them as older than they are. In the same conversation, she argued that casual comments about a girl’s body, even when made by family members, can reinforce harmful self-scrutiny at a vulnerable age.

Holmes also stressed that girls should be prepared for their first period before it arrives. She said they need to know what it may look like, what sensations are normal and why pain should not be dismissed as inevitable. That message aligns with growing clinical concern that menstrual health is often downplayed in adolescence. For girls in sport, the warning signs can be even more important: when a period disappears during intense training, it may signal Relative Energy Deficiency in Sport, or RED-S, a state in which the body is not getting enough fuel to support both activity and normal development.

The discussion also touched on conditions that can surface during the teen years, including polycystic ovary syndrome, endometriosis and premenstrual dysphoric disorder, along with the importance of preserving adolescent bone health during the years when much of lifetime bone density is laid down. Holmes framed menstruation as a vital sign rather than a nuisance, arguing that parents should pay attention not only to when a period starts but also to whether it becomes irregular, painful or absent. Her broader message was straightforward: puberty is not just a biological event, but a window into nutrition, health, development and the way girls are treated as they grow up.