Female hormones, primarily estrogen, typically start to increase significantly around the onset of puberty, which generally begins between 8 and 13 years old.
During this period, the ovaries begin to produce more estrogen, leading to the development of secondary sexual characteristics and the start of menstrual cycles. The range can vary depending on genetics, nutrition, and other environmental factors. While 8-13 is the norm, it is also possible for puberty to start earlier or later and still be within normal parameters.
