What hormonal change primarily signifies the onset of menopause?

The primary hormonal change that signifies the onset of menopause is the cessation of menstruation. Menopause is a natural biological process that marks the end of a woman's reproductive years, typically occurring in their late 40s to early 50s. During this transition, the ovaries gradually produce less estrogen and progesterone, leading to irregular menstrual cycles that eventually stop altogether.

The finality of menstruation indicates that the ovaries are no longer releasing eggs and that hormone levels are significantly lowered. While there may be fluctuations and decreases in estrogen and progesterone during the perimenopausal phase (the time leading up to menopause), the key event that characterizes menopause itself is the absence of menstrual periods for twelve consecutive months.

In this context, focusing on the cessation of menstruation helps to understand the broader hormonal changes occurring during this life stage, as the end of menstruation is a clear and observable marker of menopause rather than simply an increase or decrease in specific hormones.