The most popular prescription drug in the United States is Premarin, which contains several types of natural estrogen derived from the urine of pregnant mares. Provera is the name of a popular synthetic progestin that is commonly taken with Premarin to prevent estrogen-induced uterine cancer, but it does not prevent estrogen-induced breast cancer.
It is important to note that dangerous forms of estrogen can be produced naturally in the body, so avoiding FDA approved drugs like Premarin (which is a natural product) does not necessarily protect you against estrogen-induced cancer. The mechanisms by which estrogen causes cancer are well documented in the scientific literature. Yet, the profits generated by Premarin sales have enabled its manufacturer to create the impression that Premarin is the only estrogen replacement therapy for menopausal and postmenopausal women.
Despite the medical establishment's enthusiastic endorsement, Premarin is not for everyone. According to a 1987 survey, more than 50% of women quit estrogen therapy after a year because of side effects or because they were concerned about its long-term cancer risks. On the other hand, many women feel wonderful on Premarin and plan to take it for the rest of their lives.
The Life Extension Foundation has an alternative approach for women who are afraid of the cancer risks of long-term therapy with Premarin, or who cannot tolerate its side effects.
Forms of Estrogen
The primary forms of estrogen are:
Estradiol and estrone are potent estrogens that are vulnerable to mutation. They are the estrogens that increase your risk of breast cancer. Estriol, on the other hand, is a weak estrogen that provides anti-aging benefits, without any apparent risk of breast cancer.
Estradiol is the prime or true ovarian estrogen secreted by the ovary. Estrone is an estrogen that is synthesized from androstenedione or estradiol. While a small amount of estriol is produced by the ovary, most of the estriol found in the body is converted in the liver from estrone and by a more circuitous route from estradiol. During pregnancy, huge amounts of estriol are secreted by the placenta to protect the fetus. The urinary assay of estriol is used to assess the viability of the fetus.
Estriol is used extensively in Europe for estrogen replacement therapy in menopausal and post menopausal women, but is rarely used for that purpose in the United States. Here is some of the evidence that estriol is appropriate for estrogen replacement therapy.
Estriol Replacement Therapy
Since estriol is a weak estrogen, larger amounts must be used for estrogen replacement therapy. Estriol is used in doses of 2-to-8 mg. per day. A dose of 2-to-4 mg/day of estriol is equivalent to, and as effective as, 0.6-to-1.25 mg. of conjugated estrogens (Premarin) or estrone.
One of the most common side effects of standard estrogen therapy (Premarin), when used without a progestin, is endometrial hyperplasia, or hyper-proliferation of the cells of the uterine lining, a condition which often turns into uterine cancer.
Most investigators have found that estriol therapy, even at the high dose of 8 mg. per day, does not cause endometrial hyperplasia. In one study by scientists at the Medical College of Georgia in Augusta, 52 women with severe menopausal symptoms were given estriol succinate continuously for six months in doses of 2-to-8 mg/day.
Results of Study
Significant improvements in symptoms were noted within one month of the start of the study, and they persisted as long as estriol therapy was continued. The degree of symptom improvement was directly related to the dose. Symptom relief was moderate at 2 mg/day, but marked at 8 mg/day.
Estriol therapy also reversed vaginal atrophy and improved the quality of cervical mucus. No breakthrough bleeding occurred in any of the subjects and endometrial biopsies failed to show endometrial hyperplasia in any case, regardless of the dose of estriol used.
They concluded that: "Estriol therapy may be employed in dosages up to 8 mg/day continuously, especially in those patients in whom other estrogens induce undesired side effects such as nausea, breakthrough bleeding or endometrial hyperplasia, and the recurrence of hot flushes during cyclic therapy of more potent estrogens. Because of these features, estriol deserves a place in our therapeutic resources. Being a weak estrogen, it does not induce endometrial proliferation or breakthrough bleeding of any consequence, while modifying menopausal symptoms.
"A longer-term and larger prospective study of estriol therapy for the symptoms of the menopause was conducted by C. Lauritzen at the University of Ulm in Germany in the mid 1980s. A total of 911 patients with severe menopausal symptoms were given 2-8 mg/day of estriol succinate by 22 gynecologists at 11 hospitals in Germany for up to five years. The mean duration of the study was 2.2 years, with 121 of the patients (13.5%) receiving treatment over the entire five years of the study.
The German scientists concluded that:
"Estriol therapy was successful in 92% of all cases. In 71% hot flushes and sweating were completely eliminated, in 21% they were ameliorated, becoming weaker and occurring more seldom...Depressive moods were abolished in 24% of the cases and in 33% they were ameliorated, so that an overall improvement occurred in 57%. Also forgetfulness, loss of concentration, irritability and heart palpitations were remarkably improved towards normal. The number of patients suffering from migraine headaches decreased from 33 to 12. Atrophic changes of the vulva were completely eliminated in 44 of 61 cases and improved in 12 cases...Remarkably the quality of the skin improved according to the subjective impression of patients and physicians in a high percentage of cases...In no case, did a deterioration of symptoms occur. "