Menstrual cycle The first period usually begins between twelve and fifteen years of age, a point in time known as menarche. They may occasionally start as early as eight, and this onset may still be normal. The average age of the first period is generally later in the developing world and earlier in developed world. 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 35 days in adults (an average of 28 days). Menstruation stops occurring after menopause which usually occurs
Centre for Menstrual Cycle and Ovulation Research 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. Centre for Menstrual Cycle and Ovulation Research The Centre for Menstrual Cycle and Ovulation Research (CeMCOR) is a health research centre in Vancouver. According to the University of British Columbia, CeMCOR is the only centre in the world that focuses on ovulation and the causes and consequences of ovulation disturbances. CeMCOR is known for research on progesterone-only therapy for menopausal hot