Study Reveals Decline in Age of First Menstrual Period Among U.S. Girls

Research highlights earlier onset of menarche, particularly among minorities and lower-income groups, with links to childhood obesity.

Girls born between 2000 and 2005 start menstruating at an average age of 11.9, compared to 12.5 for those born in the 1950s and 60s.
Rates of early menarche (before age 11) and very early menarche (before age 9) have nearly doubled in recent decades.
Only 56% of girls born after 2000 achieve regular menstrual cycles within two years, down from 76% in older generations.
Childhood obesity is identified as a significant factor contributing to the earlier onset of puberty.
The study calls for more investment in menstrual health research to address potential long-term health risks.