Editing Progesterone (section)

===Skin health===
The [[estrogen receptor]], as well as the [[progesterone receptor]], have been detected in the [[human skin|skin]], including in [[keratinocyte]]s and [[fibroblast]]s.<ref name="pmid12762829">{{cite journal | vauthors = Raine-Fenning NJ, Brincat MP, Muscat-Baron Y | title = Skin aging and menopause : implications for treatment | journal = American Journal of Clinical Dermatology | volume = 4 | issue = 6 | pages = 371–378 | year = 2003 | pmid = 12762829 | doi = 10.2165/00128071-200304060-00001 | s2cid = 20392538 }}</ref><ref name="pmid16120154">{{cite journal | vauthors = Holzer G, Riegler E, Hönigsmann H, Farokhnia S, Schmidt JB | title = Effects and side-effects of 2% progesterone cream on the skin of peri- and postmenopausal women: results from a double-blind, vehicle-controlled, randomized study | journal = The British Journal of Dermatology | volume = 153 | issue = 3 | pages = 626–634 | date = September 2005 | pmid = 16120154 | doi = 10.1111/j.1365-2133.2005.06685.x | s2cid = 6077829 }}</ref> At [[menopause]] and thereafter, decreased levels of female [[sex hormone]]s result in [[atrophy]], thinning, and increased [[wrinkling]] of the skin and a reduction in skin [[elasticity (physics)|elasticity]], firmness, and strength.<ref name="pmid12762829" /><ref name="pmid16120154" /> These skin changes constitute an acceleration in [[Human skin#Aging|skin aging]] and are the result of decreased [[collagen]] content, irregularities in the [[morphology (biology)|morphology]] of [[epidermis (skin)|epidermal]] [[skin cell]]s, decreased [[ground substance]] between [[skin fiber]]s, and reduced [[capillary|capillaries]] and [[blood flow]].<ref name="pmid12762829" /><ref name="pmid16120154" /> The skin also becomes more [[dry skin|dry]] during menopause, which is due to reduced skin [[tissue hydration|hydration]] and [[sebum|surface lipids]] (sebum production).<ref name="pmid12762829" /> Along with chronological aging and photoaging, estrogen deficiency in menopause is one of the three main factors that predominantly influences skin aging.<ref name="pmid12762829" />

Hormone replacement therapy, consisting of systemic treatment with estrogen alone or in combination with a progestogen, has well-documented and considerable beneficial effects on the skin of postmenopausal people.<ref name="pmid12762829" /><ref name="pmid16120154" /> These benefits include increased skin collagen content, skin thickness and elasticity, and skin hydration and surface lipids.<ref name="pmid12762829" /><ref name="pmid16120154" /> Topical estrogen has been found to have similar beneficial effects on the skin.<ref name="pmid12762829" /> In addition, a study has found that topical 2% progesterone cream significantly increases skin elasticity and firmness and observably decreases wrinkles in peri- and postmenopausal people.<ref name="pmid16120154" /> Skin hydration and surface lipids, on the other hand, did not significantly change with topical progesterone.<ref name="pmid16120154" />

These findings suggest that progesterone, like estrogen, also has beneficial effects on the skin, and may be independently protective against skin aging.<ref name="pmid16120154" />