Menstrual cycle shortest and longest cycle lengths is considered very irregular. The average menstrual cycle lasts 28 days. The variability of menstrual cycle lengths is highest for women under 25 years of age and is lowest, that is, most regular, for ages 25 to 39. Subsequently, the variability increases slightly for women aged 40 to 44. The luteal phase of the menstrual cycle is about the same length in most individuals (mean 14.13 days, standard deviation 1.41 days) whereas the follicular phase tends to show much more variability (log-normally distributed with 95% of individuals having follicular phases between 10.3 and 16.3 days).
Centre for Menstrual Cycle and Ovulation Research stated vision was to 'reframe scientific knowledge of the menstrual cycle and ovulation in a woman-centered context.' CeMCOR is now located at Vancouver General Hospital in the Gordon and Leslie Diamond Health Care Centre. Staff includes 15 clinicians and 9 trainees. It is guided by both a Community Advisory Council and a Scientific Advisory Council composed of endocrinologists, epidemiologists, gynecologists, nutritionists, psychologists, and sociologists. 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