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CeMCOR publishes article proving progesterone builds new bone

CeMCOR (The Centre for Menstrual Cycle and Ovulation Research) has published an important article in the Journal of Musculoskeletal and Neuronal Interactions proving progesterone builds new bone.
Click here to access the full article.

Corresponding Author: Dr. Jerilynn Prior (


Proof that Progesterone Builds New Bone

Estrogen is “good for bone”, either as a menstrual cycle hormone or as a therapy. Estrogen, however, has a menstrual cycle partner hormone, progesterone, with which it collaborates throughout women’s bodies. It is controversial, however, whether or not progesterone or progestins (synthetic) that act through the progesterone bone building cell (osteoblast) receptor play any role in bone. 

In trials eligible for this innovative meta‐analysis, menopausal women were randomly assigned to estrogen alone (with built‐in endometrial safety measures) or to estrogen with progesterone/progestin whether or not they still had a uterus. These studies, for the first time, allow us to see whether progesterone or progestin add to the known bone benefits of estrogen. The results showed that there was a highly significant two‐thirds of a percentage/2‐years greater gain in spinal bone density from progestin in addition to the average 2‐3% gains caused by estrogen therapy alone.

Results of a systematic review and meta‐analysis of controlled trials just released by the Journal of Musculoskeletal and Neuronal Interactions in over 1000 menopausal women from three countries, show that progesterone adds to the spinal bone mineral density gains caused by estrogen. The studies differed from the large USA Women’s Health Initiative (WHI) trials completed over a decade ago because these compared estrogen with a placebo (in women who had undergone a hysterectomy) or estrogenprogestin with a placebo (in women with a uterus).

Although none of the available randomized controlled trials actually used progesterone, the natural women’s hormone and estradiol’s partner hormone, all eligible studies were with progestins that have been proven to that act through the osteoblast progesterone receptor (PR). Thus some progestins that resemble testosterone or are metabolized to estrogen were excluded. 

“You may ask whether the progesterone‐related added bone gain is large enough to be clinically significant,” commented Dr. Vanadin Seifert‐Klauss, a gynecologist and study co‐author from Munich. “However, trials of other bone medications acting like estrogen to decrease bone loss, show that a therapy‐related gain as small as 1% provides an 8% 10‐year decreased risk for fractures.”

“Since the WHI, estrogen alone or estrogenprogestin are no longer commonly prescribed for osteoporosis prevention or treatment,” stated Prior, first author of this study. “However, they are regularly used for treatment of hot flushes/flashes and night sweats. Estrogenprogestin is significantly more effective than estrogen alone for these. Plus the Centre for Menstrual Cycle and Ovulation Research has proven in a randomized double‐blind placebo‐controlled trial that progesterone alone is effective for hot flushes/flashes, significantly improves sleep (Hitchcock, Menopause 2012) and has no negative effects on blood clotting or heart‐related function (Prior PLOS ONE 2014).” Research is needed in co‐treatment with progesterone for women with hot flushes on osteoporosis treatment.

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 support CeMCOR research.

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
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Paperback copies (with updated insert) still available here.

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