ESTROGEN THERAPY

Below is an excerpt from Theodore Friedman M.D. Ph.D

I found the below article very useful but when reading this please don't freak out!! The side effects mentioned in the article below are actually from trials on  
PREMARIN and PROVERA

These, as the article does reveal, are NOT bioidentical. They have been made by drug companies to be similar to natural estrogens and progesterones but not IDENTICAL. This is so drug companies can patent them. You can't patent Progesterone, but you can patent Progestin as it's DNA structure has been altered. Prometrium, which is progesterone can be patented not because of the hormone but because of the delivery system.


There are risks and benefits with all medicines and estrogen therapy is no exception. In fact estrogen replacement is on of the most controversial topics in Endocrinology. This is due to conflicting data on its benefits and side effects, the multitude of available hormone replacement products and regimens and the fact that most studies on estrogen replacement have been performed using the heavily marketed estrogen preparation, Premarin. Because of its complexity, the decision about whether you should be on estrogen replacement, and equally important, what type of estrogen replacement is correct for you, needs to be carefully thought out by you and your doctor. Another controversial iaaue related to estrogen replacement is progesterone replacement. Some information on estrogen/progesterone replacement and benefits and side effects of some of the available compounds are described below.

There are both definite and positive benefits and risks of estrogens. The definite benefits include

1. Inprovement of menopause symptoms such as hot flashes, night sweats, vaginal dryness, insomnia, mood swings and depression
2. Increase in bone density leading to prevention of osteoporosis
3. A possible decrease in the chances of developing cardiovascular disease
4. A possible inprovement in good cholesterol
5. A decreased risk of colon and rectal cancer
6. A prevention of memory loss and cognitive decline

The definite risks include-

1. Endometrial cancer
2. Blood clots
3. A possible increased risk of breast cancer and galbladder disease

A recent study (the HERS study) found that estrogen actually caused women who already have heart disease to have more heart problems in the first year of taking estrogen, than women who were not given estrogen. In the additional years of the study, both groups of women had similar incidence of heart problems. It is important to emphasise that this was just one study and only evaluated women who already had heart disease.

Estrogens also have side effects. These include worsening of estrogen-dependent diseases, such as uterine fibroids and endometriosis. Other side effects include breast tenderness and breast enlargement, vaginal bleeding, high blood pressure, nausea, vomiting, headaches, jaundice and fluid retention. In general, the higher the dose, the more benefits and the more side effects are likely to occur.

Premenopausal women produce three biologically active estrogens, estrone (E1) estradiol (E2) and estriol (E3). Estradiol is the most abundant estrogen produced and both estrone and estradiol are potent estrogens. Estriol is considered a weak estrogen. Although little scientific data supports the claim, it has been postulated that estrone is a 'bad' estrogen  and may be the cause of estrogen's cancer - causing properties, while estriol is a 'good' estrogen and may protect against cancer. Estradiol is probably neutral. Oral estrogens, because they are metablolized by the liver, likely to exert different effects than systemic estrogens, which are not metabolized by the liver.

The most commonly prescribed estrogen is Premarin  PRegnantMARes uRINe, which is a conjugated equine estrogen. CEEs are harvested from the urine of pregnant mares and contain 10 different estrogen components, many of which are converted to estrone.

Another recently recognized difference between oral and systemic estrogens has to do with growth hormone (GH). GH is an important hormone made by the pituitary that stimulated the liver to produce another hormone called IGF-1. GH, via IGF-1, has many beneficial effects, including an increase in energy and sense of well-being. GH itself, has some negative effects including inducing diabetes. It has recently been found that oral, but not systemic estrogen, blocks the effects of GH on stimulating IGF-1 at the liver. Oral estrogens lead to high GH levels and also low IGF-1  levels, both with potential negative effects. This is a theoretical reason to take systemic estrogens over oral estrogens. On the other hand, oral estrogens may be more effective than systemic estrogens in terms of improving some parameters related to heart disease. Oral estrogens, but not systemic estrogens, increase the good cholesterol, HDL. Oral estrogens may have other beneficial heart effects compared to systemic estrogens.

Progesterone is usually given along with estrogen, because estrogen alone (unopposed estrogen) is associated with endometrial hyperplasia and cancer. Progesterone compounds substantially decrease this risk and are usually given along with estrogen to women with an intact uterus. What is less appreciated is that progesterone containing compounds have their own side effects and benefits. Some of the side effects include increased blood clots, rash, breast tenderness, weight gain, fatigue and somnolence, edema and nausea. Some of the possible (largely unproven) benefits include prevention of osteoporosis, improved mood and better sense of wellbeing. Similar to the issue of estrogens, there are both natural and synthetic progesterones. Synthetic progesterones are called Progestins and are the most widely prescribed Progestin is Provera. Recently, progesterone itself has become available as a drug called Prometrium. It is postulated, but not proven, that natural progesterone is better for the patient than synthetic progesterone.

The tables below of different readily available estrogen and progesterone containing compounds may be helpful. These tables are not a complete list of all available preparations, but are a guide to commonly available hormone preparations. Again I recommend that you decision on whether to start hormone replacement and if so, what type of hormone replacement, be carefully considered and arrived at in conjunction with your physician.