Estrogen Replacement

Estrogen Replacement: Overview

Estrogen replacement therapy is commonly prescribed for women as their natural estrogen levels decline due to a hysterectomy or after menopause.  Taking hormones is a decision that each woman will have to make on an individual basis.

Diagnose your symptoms now!
  • see your health summarized and in detail
  • let The Analyst™ find what's wrong
  • identify any nutritional deficiencies


Premarin®, made from a combination of estrogens including conjugated estrogens derived from pregnant mare's urine (which many argue is cruelly-obtained), has been the most commonly prescribed estrogen supplement in the U.S. for the past 50 years.  It is the estrogen used in many well-publicized studies, including the Women's Health Initiative study (where Premarin® and Prempro™ were used.)  It is important to note that the conjugated estrogens in Premarin® are not bioidentical (natural) hormones, but must be converted by the body into active estrogens.  Therefore, the results of studies using Premarin® can not necessarily be applied to bioidentical estrogens.

Bioidentical estrogens, derived from soy, are identical in chemical structure and act in the same way as the estrogen your body naturally produces.

Estrogen replacement types include Estriol, Estradiol, Biest (80% Estriol, 20% Estradiol), and conjugated estrogens (estrone combined with other estrogens, some derived from the urine of mares).  These compounds may be compounded by a pharmacist, or bought under names such as Estrace®, Estring®, Alora®, Estraderm®, Climara®, Vivelle®, FemPatch™, Menostar™, EstroGel®, Estrasorb™, Premarin®, Premphase™, Prempro™, or as their generic form.

They come in the form of oral capsules, vaginal tablets, vaginal suppositories, vaginal creams, facial serum, transdermal cream or gel, sublingual tablet, oral tablet, vaginal rings, transdermal patches, or transdermal emulsion.  Daily dosage ranges are typically 7.5mcg to 4mg.

The different forms are probably of equal efficacy.  The exception is the patches, which may not provide all the beneficial effects of oral estrogen.  They are certainly better than not taking any estrogen at all and are sometimes better tolerated than oral estrogen.  The patches don't seem to provide the same degree of beneficial effect on the cholesterol as does oral estrogen.

Why it is Recommended

Menopause usually occurs around the age of fifty years old and occurs secondary to failure of the ovaries to produce estrogen and progestin, which are the female hormones.  This is a gradual process, occasionally taking two to three years.  Symptoms vary from only the cessation periods to a multitude of annoying symptoms such as sweating, hot flashes, fatigue, vaginal drying, pain with intercourse, low sex drive and depression.  Usually these symptoms will eventually resolve even without taking hormones.  Taking estrogen will definitely stop these symptoms.

One of the long-term problems that occurs with the loss of estrogen at menopause include is the loss of calcium from the bones, causing them to become thin and brittle.  This markedly increases the risk of bone fractures.  More than 120,000 elderly women fracture their hips each year and about 15% die from complications of the hip fracture.

The process in which the bones become weak and brittle is called osteoporosis.  Collapse of the vertebrae in elderly women can occur because of the thin, weak bones.  This is responsible for the loss of height as well as the "stooped-over" appearance known as a "Dowager's hump."  Much of the bone loss occurs in the first five to ten years after menopause.

Estrogen replacement therapy stops this rapid bone loss and reduces hip fractures by 25% and spine fractures by about 50%.  Unfortunately the process of osteoporosis is not reversible with estrogen replacement therapy.  That makes it important to start hormones early after going through "the change" before the process has already resulted in weak bones.

Preliminary studies suggest that estrogen replacement therapy may also reduce the risk of Alzheimer's disease by up to 40%.

Another long-term problem due to menopause is the change in cholesterol that occurs with the loss of hormones.  The total cholesterol will increase and the good (HDL) cholesterol will decrease.  Both of these changes result in a higher likelihood of developing coronary artery disease and subsequently having a heart attack.  Estrogen replacement therapy prevents these changes and will reduce the risk of dying from a heart attack by about 35%.  This is really the most significant advantage to taking hormones after going through menopause.


As with all of the major hormones, baseline and follow-up testing of estrogen levels is critical for maintaining hormone levels in the correct range and avoiding the side-effects of supplementing with too much or too little.

NOTE: When taking estrogen alone, cells in the uterine lining can become crowded or malformed and possibly cancerous.  Therefore, for patients who still have a uterus, estrogen is often prescribed in combination with progesterone, which controls that effect and protects from endometrial abnormalities.  Testosterone, which benefits libido and bone health, may also be prescribed.  Even women who do not have a uterus and use progesterone therapy along with their estrogen experience beneficial effects with mood, fluid retention, and sleep.

Expected Outcome; Side-Effects; Counter-Indicators and Warnings

Several studies have looked at the life expectancy of women taking estrogen versus those that don't take estrogen.  In about all situations, the life expectancy is increased if you take estrogen.  This is mainly because of the lower risk of heart attacks when one takes estrogen.  The prevention of osteoporosis can also potentially save lives.  One study showed that taking estrogen after menopause was associated with an increased life expectancy of up to 2.3 years.  Heart attacks are the leading cause of death overall in females.  The annual death rate from heart disease in females in the United States is 359,000.  Anything that will reduce deaths from heart attacks by 35% will save a lot of lives.

Unfortunately there are some potential risks from taking Estrogen.  Taking estrogen (Premarin) without progestin (Provera) will increase the risk of endometrial cancer by up to eight fold.  This is why it is generally recommended that one take progestin with the estrogen.  Studies have shown that the combination of Premarin and Provera does not result in an increased risk of endometrial cancer.  In women who have had a hysterectomy, it is not necessary to take Provera since they do not have a uterus and therefore are not susceptible to endometrial cancer.  The addition of progestin to the estrogen will slightly decrease the beneficial effect that estrogen has on lowering cholesterol.

Another risk of taking estrogen is the increased chance of developing breast cancer.  There is a lot of disagreement as to whether there is truly an increased risk of breast cancer, but a general consensus is that the risk is increased by about 25% if estrogen is taken for ten to twenty years.

About 5% to 10% of women who take estrogen alone will experience side-effects such as bloating, headaches and breast tenderness.  However, in most women the symptoms are mild and will resolve after a few months of therapy.  The addition of progestin to estrogen therapy may occasionally have some undesirable side effects.  The most common are bloating, weight gain, irritability and rarely, depression.  These symptoms may also improve with time.  For the first three to six months, vaginal spotting will occur in 30% to 50% of women taking continuous estrogen and progestin.  This bleeding will generally stop permanently in about 95% of women within a six-month period.

If you have a markedly positive family history of breast cancer then the decision whether or not to take estrogen becomes more difficult.

On This Page

Estrogen Replacement:

Estrogen Replacement can help with the following:


Vaginal Dryness

Systemic hormone replacement can provide relief, as can a plant-derived safe estriol cream used locally.

Susceptibility To Miscarriages

Estrogen supplementation may be used following uterine surgery for adhesions to stimulate the regrowth of the uterine lining.

Vulvodynia / Vestibulitis

Topical estrogen creams may provide relief.  Estrogen thickens or toughens the skin and increases blood supply.  It may help you even if you have not reached menopause or do not have estrogen deficiency.  If you find vaginal creams painful (possibly from the additives such as alcohol or parabens), your physician may mix 5-10% solution in a petroleum gel base or mineral oil instead of using the standard base.

Not recommended for
Pregnancy-Related Issues

There are essentially no reasons during pregnancy why any woman would be advised to take hormones.


High Female Testosterone Level

Low estrogens allow the circulating androgens and testosterone to be more freely available and thus stimulate cells more.  Increasing the circulating estrogen in the blood by taking estrogens will increase the proteins that bind the androgens and help decrease the effects of all androgens, whether the levels are normal or excessive.


Osteoporosis - Osteopenia

Within 5 years of the initial onset of menopause, there is an accelerated rate of loss of bone, particularly from the spine.  During this period of time, estrogen replacement is somewhat effective in preventing bone breakdown, but progesterone is needed for creating new bone.  Most doctors agree that estrogen does reduce fractures (at several fracture sites) by halting the reduction in bone density.  More recent studies have shown that women who start using estrogen in their 70s still have a benefit in their 80s, and that maybe half of the dose of estrogen will do the same job.  Estrogens decrease bone resorption, but also decrease bone formation, with an overall effect of reducing loss without substantially increasing bone mass.

Concerned or curious about your health?  Try The Analyst™
Symptom Entry
Symptom Entry
Full Explanations
Optional Doctor Review
Review (optional)

Estrogen Replacement can help prevent the following:


Alzheimer's Disease

Estrogen replacement therapy may help reduce the risk of developing Alzheimer's disease or delay its occurrence, but it does not help once disease is established.

One reason for the confusion is the use of synthetic estrogens: natural estrogens should exert a protective effect.  One study found that the risk of Alzheimer's disease and related dementia for women who had used estrogen was found to be about one third below that of women who had never used estrogen.  The risk also decreased with increasing dosage and duration of estrogen therapy.  The lowest risk was observed in long-term users taking high doses.

Suggestions that the decline in estrogen levels in women at menopause might somehow make them more vulnerable to the disease have prompted interest in the hormone as a possible treatment and research has suggested that women who take estrogen are less likely to develop Alzheimer's.

However, a new study found that once the mind-robbing disease sets in, the female hormone offers no benefit.  A year of estrogen did nothing to slow the progression of the disease or improve mental functioning in 120 older women with mild to moderate Alzheimer's.  Overall, the results of this study do not support the role of estrogen in the treatment.

In another study, women aged 60 and older were given either a low estrogen dose, a high dose or a placebo every day for a year.  Instead of showing any improvement, those taking estrogen in fact fared worse than the placebo group in a rating of dementia. [JAMA February 23, 1999 283: pp.1007-1015]

[One of our doctors comments: I am really surprised that this study did not receive more widespread news coverage.  When the drug companies had the initial studies published suggesting that estrogen will help protect against Alzheimer's it was all over the news.  I was immediately confronted by many patients who felt my recommendation to avoid estrogens was unwise.  Now the evidence is in that estrogen does NOT help Alzheimer's but actually worsens it.  I am delighted that JAMA continues to take a leadership role in publishing these landmark articles which refute the drug companies' position.  Unfortunately, the conventional media still appears to be sold out – hence the lack of notification of the results of this study.

There are times when estrogen is necessary.  I believe if phytoestrogens are unable to stop the hot flashes then it would be wise to use small amounts of estrogens to stop them.  Waking up every night with hot flashes is a surefire prescription for depression and increased risk of disease.  Thus in this case the estrogen is the lesser of two evils.  It should be used for the shortest time possible and always with the intent of weaning oneself off of it.]

Report by The Analyst™
Click to see sample report
Health problems rarely occur in isolation or for obvious reasons

Your body is a highly complex, interconnected system.  Instead of guessing at what might be wrong, let us help you discover what is really going on inside your body based on the many clues it is giving.

Our multiple symptom checker provides in-depth health analysis by The Analyst™ with full explanations, recommendations and (optionally) doctors available for case review and answering your specific questions.


Moderately useful: often helps with; often prevents
Moderately useful:
often helps with; often prevents
Very useful: is highly recommended for
Very useful:
is highly recommended for
Should be avoided: is NOT recommended for
Should be avoided:
is NOT recommended for
We use cookies for traffic analysis, advertising, and to provide the best user experience