Related Topics: Bioidentical Hormones, Features, Hormones, HRT, Research, Treatments

The Safety Of Bio-Identical Hormones – Part One

Dr Dach scrutinises the evidence on bio-identical hormones and their safety in the first of a 3 part series.

Dr Jeffrey Dach

Are Women’s Bio-identical hormones safe? Bio-identical hormones exist naturally in the human body, so it is axiomatic that these are safe.  However, we are interested in a slightly different question. What is the safety of bio-identical hormones as routinely used in medical practice?  Let’s try to answer this question.

The Safety of Water compared to Bio-Identical Hormones

Water is safe, beneficial and required for health.  Yet, even so, drinking excess amounts of water causes death from Fatal Water Intoxication.  Similarly, just like water, bio-identical hormones are safe and beneficial when used at proper dosages.  Like excessive water, excessive hormone dosage may result in their own adverse side effects.  Excess estrogen, for example, causes fluid retention, breast sensitivity and enlargement, and  disordered mood.

Humans Have Bio-Identical Hormones.

Another answer to the safety question is that bio-identical hormones are found in the human body naturally.  Any harmful substance in the human body would impair survival, and over millions of years of evolution would be eliminated by natural selection.  This is the basic concept of Darwinian evolution which is accepted by mainstream medical science.

Consider the following medical experiment, performed over the last 50 million years with the help of our friend, Darwinian evolution.  Bio-Identical Hormones have been present in the human body for 50 million years, and we humans are still here on the planet.  I would consider that a successful medical experiment, wouldn’t you?

Either Excess or Deficiency of Anything Can be Harmful

One of our routine labs tests called the Chem Panel measures electrolytes and glucose levels in the blood. The body automatically maintains these within narrow ranges to maintain health.  If levels deviate above or below these normal ranges, this causes a serious health disturbance.  For example elevated potassium levels causes cardiac arrest.  Magnesium deficiency causes muscle spasm and arrythmia. Excessive amounts of Vitamins A and D are toxic.  Hormones levels enjoy a considerably wide range of acceptable limits.  Even so, a deficiency or an excess of women’s bio-identical hormones can produce adverse symptoms.  This is called estrogen deficiency/excess, and progesterone deficiency/excess, and they each have typical signs and symptoms easily recognized.

Common Signs of Estrogen Deficiency:


Day-long fatigue

Decreased sense of sexuality


Difficulty falling asleep

Dry eyes, skin, and vagina

Episodes of rapid heartbeat

Feel balanced 2nd part of cycle


Gastrointestinal discomfort

Headaches and migraines

Hot flashes

Increased back and joint pain

Lessened self-image and attention to appearance

Loss of skin radiance

Mental fogginess

Minor anxiety

Mood change

Night sweats

Pain with sexual activity

Reduced stamina

Sagging breasts and loss of fullness

Temperature swings

Weight gain

Common Signs of Excess Estrogen (takes longer to notice)

Breast tenderness or pain

Impatient, snappy behavior, but with clear mind

Increased breast size


Pelvic cramps

Water retention, fingers, legs

Common Signs of Progesterone Deficiency

Anxiety, irritability, nervousness and water retention

Breasts with lumps

Cystic breasts

Heavy and frequent periods (large clots, due to buildup in the uterus)

Most cases of endometriosis, adenomyosis, and fibroids.

No period at all (no ovulation)

Painful breasts


Spotting a few days before the period. (Progesterone level is dropping)

The period comes infrequently (every few months)

Above list courtesy of Uzzi Reiss MD OB GYN.

No Reported Adverse Events from Bio-Identical Hormones

Over-the-counter pain pills (NSAIDs) such as aspirin, naproxen and ibuprofen are considered fairly safe.  After all, you don’t need a prescription to buy them, yet they cause an estimated 16,500 deaths in the US annually, mostly from gastric bleeding.(5)  Compare this to no reported adverse events from bio-identical hormones last year, according to an FDA press conference January 2008.

Do Bio-Identical Hormones Cause Breast Cancer?

The answer is no. According to the French Cohort study, there is no increase in breast cancer in women using bio-identical hormones. However, having said that, avoiding excess environmental estrogens as well as excessive estrogen levels from any source, is the key to preventing breast cancer.(9)  My previous article covers our program for breast cancer prevention which includes iodine supplementation, Indole-3-carbinol and fiber. To read about this, see: Breast Cancer Prevention and Iodine Supplementation by Jeffrey Dach MD.

Do Bio-Identical Hormones Cause Heart Disease ?

Again, the answer is no. A study of CAT calcium scores by JoAnn E. Manson in the June 2007 JAMA actually showed less heart disease in the women taking unopposed estrogen (they had hysterectomies and were not given the synthetic progestins).  These same results had already been published 2 years previously in a calcium score study by Budoff in J Womens Health 2005. Animal studies with monkeys show that bioidentical estrogen (estradiol) prevents and inhibits heart disease.  This study was published in Arteriosclerosis by Adams in 1990.

A Closer Look at the Women’s Health Initiative WHI Study

Understanding the Women’s Health Inititative (WHI) study is not difficult, and is very important to answer the question of hormone safety.  The WHI study was the large NIH sponsored medical study which compared synthetic hormones to placebo in two large groups of women.  The WHI study consisted of two arms.  The first arm used the synthetic hormones Premarin and Provera,  and the second arm used Premarin alone.

Premarin and Provera are not bio-identical hormones.  Premarin is a hormone obtained from pregnant horses, which contains Equilin, a horse hormone not found in humans.(15)  Provera is a synthetic hormone which is not found anywhere in the natural world (see provera diagram below).(16)   The Premarin and Provera combination is called PremPro, a synthetic hormone pill commonly prescribed by mainstream medicine.  Prempro was the hormone preparation used in the first arm of the WHI study.(13)

WHI study First Arm:

The WHI study (first arm published in JAMA 2002) was terminated early because the combination of premarin and provera (Prempro) caused increased breast cancer and heart disease.(13)Immediately after this study was published, there was a massive switch by women to bio-identical hormones which resulted in a 4 billion dollar loss for Wyeth, the maker of Prempro.  Wyeth is still trying to recoup that money by manipulating the FDA.  They want the FDA to ban their competition, the bio-identical hormones or their components.

WHI Study (Second Arm):

All the women in the second arm of the WHI study had prior hysterectomies (uterus absent), so they did not need the synthetic progestin, provera commonly given to  prevent endometrial cancer.   Rather, they were only given Premarin (the horse hormone, also called CEE, for Conjugated Equine Estrogen).  Unlike the first arm of the study, these women had no increase in breast cancer risk.  Premarin causes endometrial cancer, so the mainstream medical system always gives Provera (progestins) to prevent endometrial cancer, unless of course, the uterus is absent from prior hysterectomy.

The WHI Culprit was the Synthetic Progestin (an altered form of Progesterone) so back to the first arm of the WHI which used Prempro, it is clear from the data that the  culprit which caused breast cancer and heart disease was Provera, a synthetic monster hormone.  This is nothing new.  For years, Provera has been known to cause heart disease  and breast cancer.

In fact, medical studies prove that Provera causes breast cancer.  In these studies, Primates were treated with either Progesterone or Provera showing that the Provera causes breast cancer, while the Progesterone provides protection from breast cancer.

Chemically altered hormones were used in the WHI study, and are routinely handed out by the medical system.  These altered hormones are monsters that should never have been approved for marketing to the American people.  They should be banned.


In part 2 of this article Dr Dach examines the role of the media in promoting fear of hormones and the confusion generated by their inability to distinguish between synthetic and natural hormones.

The reader is advised to discuss the comments on these pages with his/her personal physicians and to only act upon the advice of his/her personal physician.  Also note that concerning an answer which appears as an electronically posted question, I am NOT creating a physician — patient relationship.  Although identities will remain confidential as much as possible, as I can not control the media, I can not take responsibility for any breaches of confidentiality that may occur.


To read more on Dr Dach’s work please visit his website at

If you have any questions or comments on his articles you can contact him via the website

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Comments 3
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n melba | 2:53 pm, January 5th, 2017

brilliant article, really an eye opener. I have been taking soy milk for years where the estrogen concern is very strong..

table top displays | 10:47 am, August 2nd, 2012

A person necessarily lend a hand to make severely articles I might state. This is the very first time I frequented your web page and to this point? I amazed with the research you made to create this particular publish extraordinary. Excellent activity!

JR | 5:18 pm, October 6th, 2010

I take issue with some of Dr. Dach’s assertions about hormones. My thoughts:

1. If the body is as resilient and survival-oriented as he claims, then the natural decrease in bodily hormones with age must be happening for good reason. Meaning…..replacing them is unwise.

2. Hormones have specific purposes, and the likelihood for any particular one serving the express purpose of “keeping you young and healthy” seems remote.

3. Aging causes hormone decreases, NOT hormone decreases cause aging. It is most likely that the body, due to the aging process and all of the cellular assaults that come with just plain living on this planet, decreases its output of hormones because the organ systems can no longer handle the high levels of youth. Hormone means to “set in motion”. If you have the same levels as an 18 year old in a body that is aging and acquring damage, it can’t possibly be good.

4. Your own hormones can be harmful to you. Adrenaline is the most obvious example. Surges of it causes physical pain, GI upset, and make your blood pressure soar.

5. Exercise, a lifestyle factor considered “good”, redcues estrogen levels in both sexes. Excess estrogen in both men and women as they get older is linked to cancer (breast and prostate)stroke, and even dementia.

6. Being “natural” doesn’t equate with “harmless”.

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