One of the many roles of estrogen
in the body is to increase the synthesis of collagen, which is the skin's underlying support structure. Collagen also promotes skin thickness and elasticity. As men and women age, collagen production is reduced throughout our bodies, causing facial wrinkles and skin sagging. (Some women may also experience loss of vaginal lubrication and/or thinning of the vaginal wall.) Restoring hormone balance can restore the body's ability to produce collagen, which 'plumps' your skin and helps retain its youthful appearance. Collagen atrophy is a major factor in skin aging. In fact, there is a strong correlation between skin collagen loss and estrogen deficiency at menopause. The skin is an important estrogen-responsive endocrine tissue. Without the growth-promoting effects of estrogen, the skin literally withers away. Thin skin observed in the elderly can be directly correlated to lack of estrogens needed to generate collagen and maintain skin thickness.
Remember that "estrogen" is actually a term for three different hormones: Estrone (E1), Estradiol (E2), and Estriol (E3). When the term "estrogen" is used, most of the time it refers to Estradiol (E2), which is the highest concentration --80%-- during a woman's reproductive years (from puberty to pre-menopause). Estriol (E3) makes up another 10% and Estrone (E1) makes up the last 10%.
Estriol (E3) is considered a "weak" estrogen which can be derived from plant sources. It does not need to be counterbalanced by progesterone, and does not have a systemic (widespread) effect on the body. This makes estriol an ideal estrogen for topical use, since research suggests its application remains in the skin, rather than in the bloodstream. There is also evidence that estriol, (sometimes called the "good estrogen") may inhibit some of the unwanted effects of estradiol by "binding" to estrogen receptors that typically promote cell proliferation.
Transdermal (or topical) estriol has been shown to be safe and effective in preventing skin aging. In a study
published in February 2007, a group of women were given a topical 0.01% estrogen cream. After only four months, skin thickness was enhanced and collagen levels increased. This study demonstrated that topical estrogen application provided quick and measurable anti-aging effects (even in women who had relatively normal estrogen blood levels). Other studies have investigated the beneficial role that estrogens, especially estriol, can play in maintaining skin firmness, elasticity, moisture content, and even wound healing.
Another such study
was conducted at the University of Vienna in Austria, comparing the topical application of 0.3% estriol and 0.01% estradiol creams over a six-month period. Researchers found that skin symptoms of aging improved, and that those treated with estriol obtained superior results, with no systemic hormonal side effects noted. The results of the study noted: "...elasticity and firmness of the skin had markedly improved and the wrinkle depth and pore sizes had decreased by 60 to 100% in both groups. Skin moisture had increased and the measurement of wrinkles using skin profilometry, revealed significant, or even highly significant, decreases of wrinkle depth in the estradiol and estriol groups, respectively... significant increases of collagen labeling were combined with increased numbers of collagen fibers...No hormonal side effects noted."