J Eur Acad Dermatol Venereol. 2013 Oct;27(10):1236-43.
"Reactive oxygen species (ROS) cause severe damage to extracellular matrix and to molecular structure of DNA, proteins and lipids. Accumulation of these molecular changes apparently constitutes the basis of cell ageing. 17b-estradiol (E2) has a key role in skin ageing homeostasis as evidenced by the accelerated decline in skin appearance seen in the perimenopausal years. Oestrogens improve many aspects of the skin such as skin thickness, vascularization, collagen content and quality. Despite these clinical evidences, the effects of oestrogens on skin at the cellular level need further clarification."
"In this study we highlight that the menopause-associated oestrogens decline is involved in reduced collagen production and that E2 could counteract the detrimental effects of oxidative stress on the dermal compartment during skin aging. Furthermore, our data show that physiological concentrations of oestrogens are able to interfere with ROS-mediated cell viability reduction and to protect human skin cells against oxidative damage to cellular membranes and nucleic acids structure."
"Our experimental data show that the presence of 17β-estradiol may protect skin cells against oxidative damage and that the dramatic lowering of oestrogen levels during menopause, could render skin more susceptible to oxidative damage."
Rejuvenation Res. 2012 Jun;15(3):302-12.
"Prevention of skin aging by estrogen/progesterone replacement therapy is effective if administered early after menopause and influences intrinsically aged skin only."
Maturitas. 2001 Jul 25;39(1):43-55.
"Mean levels of epidermal skin moisture, elasticity and skin thickness were improved at the end of treatment based on both subjective and objective evaluation in patients with hormone replacement therapy (HRT). Skin surface lipids were increased during combined HRT, which may reflect stimulatory effects of the progestagen component on sebaceous gland activity, while oestrogen alone has a sebum-suppressive action."
Climacteric. 2007 Aug;10(4):289-97.
"Estrogens have a profound influence on skin. The relative hypoestrogenism that accompanies menopause exacerbates the deleterious effects of both intrinsic and environmental aging. Estrogens prevent skin aging. They increase skin thickness and improve skin moisture. Beneficial effects of hormone replacement therapy (HRT) on skin aging have been well documented"
Ann Endocrinol (Paris). 2006 Dec;67(6):575-80.
"Estrogen treatment in post menopausal women has been shown to increase collagen content, dermal thickness and elasticity. Biophysical properties are also significantly improved for the parameters reflecting hydration and sebum secretion."
Br J Dermatol. 2005 Sep;153(3):626-34.
"The results of this study demonstrate that topical (...) progesterone acts primarily in increasing elasticity and firmness in the skin of peri- and postmenopausal women. These effects in combination with good tolerability make progesterone a possible treatment agent for slowing down the ageing process of female skin after onset of the menopause."
I can personally vouch for its effects on my skin, especially when I started taking oral micronized progesterone combined with injectable E.
