Safety of Bioidentical Hormones


Bioidentical Hormones for Safety and Efficacy.

The use of synthetic female hormones will go   down in history as one of the worst failed medical experiments of all time.  The most widely prescribed estrogen called Premarin doesn’t come from humans.  It comes from pregnant horse urine.  The most widely prescribed synthetic progesterone called Provera is a chemical which is not normally found in the human body or anywhere else in the animal or plant kingdom.  After 30 years in medical practice, I have been astounded by the fact that our medical system uses these synthetic hormones.  However, if you consider the financial implications, this is not surprising. Current law prohibits patent protection for the manufacture of natural substances like human estrogen and human progesterone. However, the Synthetic versions can be patented and therefore profitable.

Bio-Identical Hormones:

Bio-Identical hormones are inexpensive and these are the ones found in the human body.  They are readily available from compounding pharmacies.   The medical literature confuses the definition of Synthetic and Bio-Identical Hormones and doesnt understand the difference.  That is why the large medical studies on hormones such as the Womens Health Initiative have used only synthetic hormones which have patent protection.  The WHI study was published in the July 2002 issue of JAMA.

The WHI study shows increased Cancer and Heart Disease from Synthetic Hormones:

The first arm of the WHI study was halted early because of increased breast cancer in the Synthetic Hormone group.  The culprit was found to be the Synthetic Progesterone, Provera, which also causes coronary vasospasm, heart disease and stroke.  A less well known study, published in JAMA 2004, was  the second arm of the WHI study, which used Horse Estrogen (Premarin) alone.  This study actually found less breast cancer in the Premarin treated group.  However, the oral estrogen pill was causing blood clots and strokes (similar to the birth control pills) and this study was also halted early. Out of 5,300 patients, there were 124 cases of breast cancer per year in the placebo group (dummy pill) and only 94 cases in the Premarin treated group.

A Clinical Study showing Safety of Bio-Identical Hormones:

The French Cohort Study showed no increased risk of breast cancer from Bio-identical hormones in 3,000 women.

Dr. Joseph F. McWherter conducted a clinical study involving 2,300 women on his Bio-Identical Hormone Program over a five year period.  He reports only one case of breast cancer under his care over five years.  Compare this to the 124 cases of breast cancer expected each year from the Womens Health Initiative study, and it is clear that Dr McWherters patients had a dramatic reduction in breast cancer.  This excellent result can be credited to the Breast Cancer Prevention Program outlined in his book.

By Dr Jeffrey Dach, M.D.

My Comments:  This well researched articles puts the case for the benefits and safety of BHRT very clearly.


Climacteric. 2012 Apr;15 Suppl 1:3-10.

What’s new in hormone replacement therapy: focus on transdermal estradiol and micronized progesterone.


Department of Obstetrics and Gynecology, George Washington University, Washington, DC 20036, USA.


The original conclusions of the Women’s Health Initiative study have been questioned as a result of the availability of age-stratified data. Initial concerns regarding the risk of coronary heart disease (CHD) in association with the use of hormone replacement therapy (HRT) have been replaced with concerns regarding thromboembolic disease, encompassing venous thromboembolism (VTE), particularly in younger postmenopausal women, and stroke, particularly in older women. The original publication of the study results led to a dramatic decrease in the use of oral HRT; however, the use of transdermal HRT has increased over recent years.

 Guidelines from the North American Menopause Society, the Endocrine Society, the International Menopause Society, and specific guidelines from the Menopause and Andropause Society for the management of menopausal women with a personal or family history of VTE all contain positive statements regarding both transdermal estradiol and micronized progesterone.

Unlike oral estrogens, transdermal estradiol has been shown not to increase the risk of VTE, or stroke (doses ≤ 50 μg), and to confer a significantly lower risk for gallbladder disease. Unlike some progestogens, progesterone is also not associated with an increased risk of VTE, or with an increased risk of breast cancer. Based on these data, which are now included in the guidelines, the use of transdermal estradiol and micronized progesterone could reduce or possibly even negate the excess risk of VTE, stroke, cholecystitis, and possibly even breast cancer associated with oral HRT use

They reviewed all the guidelines form the major medical bodies that deal with hormones, and concluded that using transdermal oestrogen and micronised progesterone is the safest form of HRT.  Micronised is the form of natural progesterone used in Bioidentical HRT. This is not to be confused with progestogens, which is used mainly in the synthetic forms of HRT Progestogens largely are known as Provera, {Medroxyprgesterone acetate- MPA: or Norethisterone (Primolut-N).

This is the most recent medical publication re safety of HRT:

Menopause. 2016 Jul 25. [Epub ahead of print]

Reduced risk of breast cancer mortality in women using postmenopausal hormone therapy: a Finnish nationwide comparative study.

Author information

  • 11Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland 2Folkhälsan Research Center, Biomedicum, Helsinki, Finland 3EPID Research Oy, Espoo, Finland 4Information Services Department, National Institute for Health and Welfare, Helsinki, Finland.



Data are controversial on the impact of postmenopausal hormone therapy (HT) on breast cancer mortality. We analyzed nationwide Finnish data on breast cancer mortality risk in women using HT consisting of estradiol-only therapy (ET) or estrogen-progestogen therapy (EPT).


In total, 489,105 women using HT in 1994 to 2009, traced from the nationwide reimbursement register, were followed from the HT initiation (3.3 million cumulative exposure years) to breast cancer death (n = 1,578 women). The observed deaths were compared with those in the age-standardized background population.


The breast cancer mortality risk was reduced in all HT users with exposure for at most 5 years (standardized mortality ratio 0.56; CI 0.52-0.60), more than 5 to 10 years (0.46; 0.41-0.51), or more than 10 years (0.62; 0.56-0.68). A significantly larger risk reduction was detected in the 50 to 59 years age group (0.33; 0.29-0.37) compared with 60 to 69 (0.64; 0.59-0.70) or 70 to 79 (0.78; 0.69-0.87) years age groups. The death risk reductions in ET users tended to be larger in all age groups compared with EPT users, with a significant difference only in the 70 to 79 years age group (0.66; 0.57-0.76 vs 0.88; 0.77-1.00). The age at HT initiation, regardless whether ET or EPT, showed no association with breast cancer mortality.


In the Finnish unselected population, breast cancer is fatal in 1 of 10 patients. Our data imply that this risk is prevalent in 1 of 20 patients with history of HT use. This is an important message for women considering or already using HT.

Menopause. 2015 Sep;22(9):976-83. doi: 10.1097/GME.0000000000000450.

Estradiol-based postmenopausal hormone therapy and risk of cardiovascular and all-cause mortality.



Data on the health benefits and risks of postmenopausal hormone therapy (HT) are derived mainly from the use of conjugated equine estrogens. Estradiol-based regimens may have a different risk-benefit profile. We evaluated the risk of death caused by coronary heart disease (CHD), stroke, or any disease among users of estradiol-based HT regimens in a nationwide study in Finland.


A total of 489,105 women who used HT from 1994 to 2009 (3.3 million HT exposure years), as indicated in the nationwide reimbursement register and the national Cause of Death Register, were followed. A total of 28,734 HT users died during follow-up; among the deaths, 3,843 were caused by CHD and 2,464 were caused by stroke. Mortality risk in HT users with varying duration of exposure (≤1 y, >1 to 3 y, >3 to 5 y, >5 to 10 y, or >10 y) was compared with that in an age-matched background population.


Risk of CHD death was significantly reduced by 18% to 54% in HT users and was positively related to HT exposure time. Risk of stroke death was also reduced by 18% to 39%, but this reduction was not clearly related to HT exposure time. Risk of all-cause mortality was reduced in HT users by 12% to 38%, almost in linear relationship with duration of exposure. All these risk reductions were comparable in women initiating HT before age 60 years and women initiating HT at age 60 years or older.


In absolute terms, the risk reductions mean 19 fewer CHD deaths and 7 fewer stroke deaths per 1,000 women using any HT for at least 10 years.

J Clin Endocrinol Metab. 2017 Mar 1;102(3):870-877. doi: 10.1210/jc.2016-3590.

Lower Death Risk for Vascular Dementia Than for Alzheimer’s Disease With Postmenopausal Hormone Therapy Users.



There are conflicting data on postmenopausal hormone therapy (HT) and the risk of vascular dementia (VD) and Alzheimer’s disease (AD).


We analyzed the mortality risk attributable to VD or AD in women with a history of HT use.

Design, Patients, Interventions, and Main Outcome Measures:

Finnish women (n = 489,105) using systemic HT in 1994 to 2009 were identified from the nationwide drug reimbursement register. Of these women, 581 died of VD and 1057 of AD from 1998 to 2009. Observed deaths in HT users with <5 or ≥5 years of exposure were compared with deaths that occurred in the age-standardized female population. Furthermore, we compared the VD or AD death risk of women who had started HT at <60 vs ≥60 years of age.


Risk of death from VD was reduced by 37% to 39% (<5 or ≥5 years of exposure) with the use of any systemic HT, and this reduction was not associated with the duration or type (estradiol only or estradiol-progestin combination) of HT. Risk of death from AD was not reduced with systemic HT use <5 years, but was slightly reduced (15%) if HT exposure exceeded 5 years. Age at systemic HT initiation (<60 vs ≥60 years) did not affect the death risk reductions.


Estradiol-based HT use is associated with a reduced risk of death from both VD and AD, but the risk reduction is larger and appears sooner in VD than AD.

Int J Gen Med. 2014 Sep 1;7:433-40. doi: 10.2147/IJGM.S46310. eCollection 2014.

Prevention and treatment of venous thromboembolism during HRT: current perspectives.


Many large trials in the past 15 years have proven an increased risk of vascular complications in women using oral, mostly non-bioidentical, hormone therapy. The risk of vascular complications depends on the route of administration (oral versus transdermal), age, duration of administration, and type of hormones (bioidentical versus non-bioidentical). Acquired and/or hereditary thrombophilias (eg, factor V Leiden, prothrombin mutation G20210A, and others) lead to a further increase of risk for venous thromboembolism, stroke, or myocardial infarction. Therefore, bioidentical hormone therapy via the transdermal route seems to be the safest opportunity for hormone replacement therapy, although large trials for bioidentical hormone therapy are needed.

Research now shows that HRT of any sort is very safe. We now know this because we have been able to compare hundreds of thousands of women on HRT with an equal number not on HRT.  What we now know is that:

-HRT reduces the risk of Heart disease. Remember over 50% of women over 50 years of age will die of heart disease.(see” HRT and heart disease” on this website for the evidence)

-Women on HRT have less deaths from any cause  than those not on HRT. However, this only applies to women if they start HRT under the age of 60, or within 10 years of menopause.(I have provided the evidence throughout this website.)

-Women who start HRT early and use it for more than 10 years are not at significantly increased risk of breast cancer or stroke.(See “Breast cancer and HRT”)

-Bioidentical (natural) hormones are even safer, especially the use of natural progesterone.(See below)

-HRT should be given through the skin, and not as a pill.(see below)

-The basic principle is very simple: Different women require a different dose, by a different route, of different combinations of different hormones, for different symptoms. One size does not fit all.

The evidence supporting the above statements is provided below, for those interested in wading through  some of the many scientific and medical studies done on this subject.

There now has been numerous studies on BHRT which prove the effectiveness and safety of BHRT. More information is available at the chapters Evidence for BHRT and Natural HRT vs Synthetic HRT- The Facts. Below is the most recent and highly credentialed study – reported in the British Medical Journal, the highly esteemed medical journal.

Effect of hormone replacement therapy on cardiovascular events in recently postmenopausal women: randomised trial

BMJ  2012; 345 doi: 9 October 2012)
Cite this as: BMJ 2012;345:e6409


Objective To investigate the long term effect of hormone replacement therapy on cardiovascular outcomes in recently postmenopausal women.

Results At inclusion the women on average were aged 50 and had been postmenopausal for seven months. After 10 years of intervention, 16 women in the treatment group experienced the primary composite endpoint compared with 33 in the control group (hazard ratio 0.48, 95% confidence interval 0.26 to 0.87; P=0.015) and 15 died compared with 26 (0.57, 0.30 to 1.08; P=0.084). The reduction in cardiovascular events was not associated with an increase in any cancer (36 in treated group v 39 in control group, 0.92, 0.58 to 1.45; P=0.71) or in breast cancer (10 in treated group v 17 in control group, 0.58, 0.27 to 1.27; P=0.17). The hazard ratio for deep vein thrombosis (2 in treated group v 1 in control group) was 2.01 (0.18 to 22.16) and for stroke (11 in treated group v14 in control group) was 0.77 (0.35 to 1.70). After 16 years the reduction in the primary composite outcome was still present and not associated with an increase in any cancer.

Conclusions After 10 years of randomised treatment, women receiving hormone replacement therapy early after menopause had a significantly reduced risk of mortality, heart failure, or myocardial infarction, without any apparent increase in risk of cancer, venous thromboembolism, or stroke.



More recent evidence appeared in the Climacteric journal – the official journal of the North American Menopause Society.

My Comments:  This well researched articles puts the case for the benefits and safety of BHRT very clearly.


Climacteric. 2012 Apr;15 Suppl 1:18-25. doi: 10.3109/13697137.2012.669584.

Micronized progesterone and its impact on the endometrium and breast vs. progestogens.


Unité de Gynécologie Endocrinienne, APHP, Cochin-Port Royal, Paris, France.


It is well established that progestogens protect the endometrium against the proliferative effects of estrogens in postmenopausal women receiving hormone replacement therapy (HRT). Therefore, micronized progesterone and progestogens are recommended as part of combined HRT in women with an intact uterus. The protective effect of progestogens against hyperplasia and endometrial cancer does not appear to differ with different progestogens (micronized progesterone or progestogens), but appears to be affected by the regimen and thus the dose, with continuous combined treatment conferring better protection. However, the protective effect of progestogens seen in the endometrium is not replicated in the breast. Progestogens combined with estrogens are generally associated with a small increase in the risk of invasive breast cancer, which is believed to be due to a promoter effect. However, all progestogens are not equivalent in their effects on the breast and breast cancer risk. Micronized progesterone does not increase cell proliferation in breast tissue in postmenopausal women compared with synthetic medroxyprogesterone acetate (MPA). Experimental evidence suggests that the opposing effects of MPA and micronized progesterone on breast tissue are related to the non-specific effects of MPA, including glucocorticoid activity and differences in the regulation of gene expression. Therefore, for women with an intact uterus, micronized progesterone may be the optimal choice as part of combined HRT.

[PubMed – indexed for MEDLINE]
Feel free to comment below. I welcome input.

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