ESTRIOL prevents menopausal symptoms. E.g. hot flashes, without causing unwanted side effects common to conventional estrogen replacement therapy.
- Vaginal dryness, atrophy (leading to vaginitis and cystitis). Beneficial acid-producing vaginal Lactobacilli depend on the presence of estrogen. ESTRIOL has a binding affinity to vaginal ERs equal to ESTRADIOL, sufficient to exert a full effect on the vagina after a single dose. For postmenopausal vaginal dryness and atrophy, which can lead to vaginitis and cystitis, ESTRIOL supplementation is theoretically the most effective and safest estrogen choice.
Study shows ESTRIOL modifies the vaginal flora and significantly lowers vaginal pH (from 5.5 to 3.8).
- ESTRIOL recolonized Lactobacilli (absent prior to therapy) in the vagina after only one month. In 61% of postmenopausal women given ESTRIOL, but in none receiving placebo.
- Additionally, the prevalence of Enterobacteriaceae (fecal bacteria) colonization fell from 67% to 31%. No change observed in those receiving placebo. (Cardozo et al,1998)
The intravaginal administration of ESTRIOL prevents recurrent UTIs in postmenopausal women
Intra-vaginally applied ESTRIOL cream significantly reduced UTI incidences in women with recurrent UTIs - in a randomized, double blind, placebo-controlled study the group of women using intravaginal ESTRIOL cream (containing 0.5 mg ESTRIOL, once daily for two weeks, then twice weekly for eight months) had dramatically reduced incidence of UTI compared with placebo (0.5 versus 5.9 episodes per year). Raz & Stamm, 1993)
The intravaginal administration of ESTRIOL reduced incontinence in postmenopausal women. In a randomized, placebo-controlled study, 88 women were given 2 mg intravaginal ESTRIOL suppositories (once daily for two weeks, then twice weekly for six months) or placebo. Of the women in the ESTRIOL group, 68% reported improvement in symptoms of incontinence. In addition, measurements of mean maximal urethral pressure and mean urethral closure pressure were significantly improved. (Dessole et al, 2004)
ESTRIOL may offer cancer-protective benefits for post menopausal women without the side effects of ESTRADIOL
- ESTRIOL's WEAKNESS IS ITS STRENGTH. ESTRIOL has a much less stimulating effect on the breast than ESTRONE and ESTRADIOL (which is 1000 times more stimulating to breast tissue)
• ESTRIOL blocks ESTRONE and ESTRADIOL activity. ESTRIOL binds to estrogen receptors (ERs) on the breast cells, but has much weaker activity. Thus, it actually blocks the stronger ESTRONE and ESTRADIOL from binding to those cells and subjecting them to the subsequent higher estrogenic activity.
• ESTRIOL ▲ correlates with cancer▼. In the 1966 Journal of the American Medical Association H.M. Lemmon, M.D. reported a study showing that higher levels of ESTRIOL in the body correlate with remission of breast cancer. Dr. Lemmon demonstrated that women with breast cancer had reduced urinary ESTRIOL excretion. He also observed that women without breast cancer have naturally higher ESTRIOL levels, compared to ESTRONE and ESTRADIOL levels, than women with breast cancer.
- Vegetarian and Asian women have high levels of ESTRIOL (presumed to be the result of a high intake of phytoestrogenic soy) and these women are at much lower risk of breast cancer than other women
- ESTRIOL has a much less stimulating effect on uterine lining than ESTRADIOL
• Receptor binding studies have indicated that ESTRIOL has a binding affinity to endometrial estrogen receptors only about 10% of ESTRADIOL. After a single dose (as opposed to a continuously supplied dose) of ESTRIOL, the binding to the endometrial estrogen receptor is too short to induce proliferation
Unlike the stronger estrogens ESTRADIOL or estrone, ESTRIOL has not been shown to stimulate the uterus or breast cells either. In either animal studies or human clinical trials.
A clinical trial of 2.5 to 5 mg per day of ESTRIOL therapy in 28 premenopausal and postmenopausal breast cancer patients demonstrated that estriol induced remission or arrest of metastatic tumors in six (37%) of the women.
Estrogens are needed for producing the proteins collagen and elastin. These give skin its elasticity and structure, and also hyaluronic acid, responsible for holding moisture in the skin.
- Collagen is lost at a rate of ~30% in first 5 years after menopause. Then ~ 2.1%/year over 20 years.
- Mid/Late 1990's studies demonstrated that ESTRIOL face cream is very effective at reversing wrinkles and other skin aging problems occurring at menopause
- You need a "Goldilocks" Dose" of ESTRIOL. i.e. it must be just right, because estrogen levels too high or too low give lower collagen levels.
Estrogen replacement therapy significantly increases dermal skin thickness. Determined by various studies.
- Estrogen therapy in castrated mice increased GAG content by 70% in 2 weeks. In women, increases in GAGs lead to skin thickness increases that are much higher than from collagen content increases alone;
Some menopausal women taking oral ESTRIOL experienced a significant decrease in both systolic and diastolic blood pressure. These women took 2 mg/day oral ESTRIOL for 12 months. (Takahashi et al, 2000)
Some elderly women taking ESTRIOL decreased their total cholesterol and triglycerides and increased their levels of beneficial HDL cholesterol. The study evaluated 20 postmenopausal and 29 elderly women taking an oral Estriol dose of 2 mg/day for 10 months. (Nishibe et al, 1996)
Japanese study of 75 postmenopausal women supplementing ESTRIOL showed increases in bone mineral density, a decrease in menopausal symptoms, and no increased risk of endometrial hyperplasia (tissue overgrowth that may precede cancer). After 50 weeks of taking 2 mg/day of ORAL estriol cyclically and 800 mg/day of calcium lactate. (Minaguchi et al, 1996)
Another study found that supplementing estriol in addition to calcium lactate significantly increased bone mineral density compared to calcium supplement alone. Postmenopausal and elderly women took 2 mg/day of ORAL estriol and 1,000 mg/day of calcium lactate versus 1,000 mg/day calcium lactate alone. (Nishibe et al, 1996)
Cardozo L, Bachmann G, McClish D, Fonda D, Birgerson L. (1998) Meta-analysis of estrogen therapy in the management of urogenital atrophy in postmenopausal women: second report of the hormone and urogenital therapy committee. Obstet Gynecol ;92:722-7.
Dessole S, Rubattu G, Ambrosini G et al (2004 Jan) Efficacy of low-dose intravaginal estriol on urogenital aging in postmenopausal women. Menopause. ;11(1):49-56.
Minaguchi H, Uemura T, Shirasu K, et al (1996 Jun) Effect of estriol on bone loss in postmenopausal Japanese women: a multicenter prospective open study. J Obstet Gynaecol Res.;22(3):259-65.
Nishibe A, Morimoto S, Hirota K, et al (1996 May) Effect of estriol and bone mineral density of lumbar vertebrae in elderly and postmenopausal women. Nippon Ronen Igakkai Zasshi. 33(5):353-9.
Raz R, Stamm WE (1993) A controlled trial of intravaginal estriol in postmenopausal women with recurrent urinary tract infections.N Engl J Med ;329:753-7.
Takahashi K, Okada M, Ozaki T, et al (2000 May) Safety and efficacy of oestriol for symptoms of natural or surgically induced menopause. Hum Reprod.; 15(5):1028-36.
