Definitions for "Premenopause"
refers to women from menarche until perimenopause. Before perimenopause was understood, this term described any menstruating woman.
The period between menarche (the first menstrual period) and the onset of perimenopause.
See Perimenopause Progesterone: Endogenous hormone produced in the corpus luteum. Promotes proliferation of uterine mucosa and prevents further follicular development.