Prior, Jerilynn

Prior, Jerilynn

Faculty of Medicine, Division of Endocrinology
Scientific Director, Centre for Menstrual Cycle and Ovulation Research


Jerilynn C. Prior BA, MD, FRCPC, ABIM, ABEM is a Professor of Endocrinology and Metabolism at the University of British Columbia in Vancouver, B.C.
She has spent her career studying menstrual cycles and the effects of the cycle’s estrogen and progesterone hormones on women’s health. She is the founder (2002) and Scientific Director of the Centre for Menstrual Cycle and Ovulation Research (CeMCOR). CeMCOR is actively researching women’s health and has a very accessible, informative website that receives on average between 3500-5000 page views per day ( She is also Director of the BC Centre of the Canadian Multicentre Osteoporosis Study (CaMOS) that is studying osteoporosis, fractures and bone density and has followed over 9000 adult women and men across the country for over 16 years, plus about a 1000 youth ages 16-24 for two years.

Dr. Prior has studied women’s menstrual cycles, perimenopause and the causes for and treatment of osteoporosis. CeMCOR/Prior has shown that regular cycles (with enough estrogen) commonly do no produce sufficient progesterone (anovulation or short luteal phases). More versus fewer ovulatory disturbances within regular cycles are related to significant spinal bone loss in healthy women ages 20-45. She has shown in controlled trials that the ovarian hormone, progesterone, is effective treatment for menopausal hot flushes. She also documented in a 3-months trial that progesterone is safe for heart health. Dr. Prior is internationally known for her research showing that progesterone increases bone formation by stimulating osteoblasts. More recently, she has documented that estrogen levels, besides being unpredictable, are significantly higher than normal in the perimenopause, the 3-10 years of changes before menopause. She is widely sought as a speaker for professional and lay audiences and is the author of the award-winning book Estrogen’s Storm Season: Stories of Perimenopause, an informative book about perimenopause told in story format. Estrogen‘s Storm Season was a finalist in the 2006 Independent Publishers Book Awards for Health. With Susan Baxter PhD, sociologist/medical journalist, Prior is author of Estrogen Errors – Why Progesterone Is Better For Women’s Health (2009). This book aims to inform women of the decades of presumption and prejudice behind estrogen-centric women’s health dogma. She has authored scientific papers numbering over 200 and holds 6 patents. She is an Honourary Alumna of the University of British Columbia Faculty of Medicine and was awarded its Distinguished Medical Research Lecturer Award (2002). She has numerous other honours including the Ann Voda Lifetime Achievement award of the Society for Menstrual Cycle Research.

Research Themes:

Reproductive Infectious Diseases Sexual and Reproductive Health

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