Menstruation
Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. The first day of menstrual bleeding is the date used for the last menstrual period (LMP). The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women, and 21 to 31 days in adults (an average of 28 days).
Centre for Menstrual Cycle and Ovulation Research
CeMCOR published over 50 scientific papers in its first 10 years, as well as 4 books. Areas of research include menstruation and ovulation, bone health, premenopausal breast cancer, polycystic ovary syndrome (PCOS), and perimenopause. CeMCOR has stated that its research shows overall that regular menstrual cycles with ovulation help prevent osteoporosis, breast cancer, and heart disease. Dr. Prior has called menstrual cycles "a vital sign".
CeMCOR does not conduct research funded by the pharmaceutical industry.