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Celebrating CeMCOR’s 22 Years of Saying “Ovulation Matters”


Jerilynn C. Prior BA, MD, FRCPC

Twenty-two years ago this month, with $20,000 from a Department of Medicine award to me and $20,000 from Vancouver Coastal Health Research Institute (VCHRI), we started the Centre for Menstrual Cycle and Ovulation Research (CeMCOR) with a part-time executive director, Joanne Silver (now deceased) and a party at Vancouver General Hospital she organized. The centre launched with the support of a Community Advisory Council led by Dorothy Stowe (deceased Greenpeace cofounder, children’s advocate and Quaker) and a Scientific Advisory Council with Drs. Susan Love (of USA breast cancer fame, now deceased) and Susan Barr (UBC emerita professor of nutrition).  

CeMCOR’s vision then was and still is: “To reframe scientific knowledge of the menstrual cycle and ovulation in a woman-centred context.” We continue to be the only organization in the world dedicated to preventing and treating ovulatory disturbances. 

To advance our vision, we created a website with plain-language, helpful materials for adolescents with cramps, premenopausal women with polycystic ovary syndrome (PCOS), perimenopausal women with night sweats and sleep problems, and menopausal women deciding whether or not to take Menopausal Hormone Therapy. The CeMCOR website consistently garners >3,000 page-views/day and has drawn visitors from over 200 countries.

What has CeMCOR learned over these 22 years? We can summarize it this way:  

Ovulation reflects women’s well-being and predicts lifelong good health.  

By “ovulation” we mean that a menstrual cycle releases an egg and starts making progesterone as well as estrogen. We’ve learned that estrogen and progesterone are essential partners in premenopausal women’s hormonal and overall health. The activity of estrogen, women’s powerful growth-stimulating hormone, needs to be in balance with progesterone, which makes tissues mature and counterbalances estrogen-related over-growth. We’ve done the science to show that being in estrogen-progesterone balance mostly always over the 25-45 menstruating years is essential for optimal breast, brain, bone, heart, and uterine health, as well as for being fertile (if desired).

During the SARS-CoV-2 pandemic, with 108 community women, we learned that despite 9 of 10 cycles being clinically normal, 32% were without ovulation and 31% were ovulatory but with too little progesterone production to counterbalance estrogen and support fertility. Given the multiple stresses of the pandemic—including not eating, overeating, over-working, emotional isolation, anxiety, fear and/or abuse—the hypothalamus protected women+ from the demands of progesterone. It protected by first suppressing ovulation. Prolonged, multiple stressors also cause far-apart periods (oligomenorrhea) or loss of menstruation for many months (amenorrhea). Cycles are more commonly protectively suppressed in teens whose reproductive system has not yet reached full, ovulatory maturity. 

We’ve further learned that, for women with hypothalamic adaptive, reversible reproductive suppression, cyclic progesterone therapy—giving 300 mg of oral micronized progesterone at bedtime for two weeks of every month/menstrual cycle—will prevent bone loss and even cause bone gain. With improved knowledge and correction of the “stressors,” cyclic progesterone can stimulate normal ovulation and menstrual cycle recovery. 

In 2023, we published a randomized controlled trial showing that daily progesterone (300 mg at bedtime) effectively treats perimenopausal night sweats, sleep and perimenopausal interference with daily life. Our latest break-through is a pilot study showing that cyclic progesterone markedly improved health-related quality of life in PCOS.  

With this newsletter we are announcing an exciting CeMCOR brand re-fresh and our plans to update and improve the CeMCOR website.


I am now, at almost age 81, in a gradual process of retirement from UBC that will be complete by July of 2025. At present there are no UBC plans to fund another academic to lead CeMCOR and no funds to support the CeMCOR website and local research. We are inviting all those who’ve benefitted from CeMCOR’s research and shared information, to implore the University of British Columbia and the Province of BC provide funding to Sustain CeMCOR.  

We need a Professorship in Women’s Health in Endocrinology to academically lead CeMCOR. We also require about $150,000 a year to sustain local research and website activities.

I am deeply grateful to all of you who have volunteered, worked with us, and, for years, supported CeMCOR with your donations. Thank you to all those who are now willing to actively work to Sustain CeMCOR.  

Why not help CeMCOR continue our important work!
Click to Sustain CeMCOR



Estrogen’s Storm Season: Stories of Perimenopause

Estrogen's Storm Season

by Dr. Jerilynn C Prior

New second edition available

Estrogen’s Storm Season is now available in BOTH print and eBook (Mobi and ePUB) versions!

All royalties are recieved in our Endowment fund (overseen by UBC) and support CeMCOR's research and future.

It is full of lively, realistic stories with which women can relate and evidence-based, empowering perimenopause information. It was a finalist in 2006 for the Independent Publisher Book Award in Health.

Purchase your ebook copy via our Amazon Kindle or
Google Play storefronts!

Paperback copies (with updated insert) still available here.

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