Bioactives for Estrogen-Deficient Skin: Topical and Oral Supplement Clinical Studies. A Narrative Review.

Bioactive compound applications by topical or oral administration have gained increased utilization/awareness in providing health benefits particularly due to changes in hormone levels and aging, especially in women with the decline and loss of estrogens. This narrative review focuses on the bioactive compounds such as the phytoestrogens that have estrogenic properties for improving skin health. Notably, phytoestrogens bind and/or activate estrogen beta receptors, which are abundant in skin layers to improve dermal health. This review presents: (a) skin characteristics with aging in women, (b) changes in hormone levels with aging in women (especially with estrogen deficiency), (c) the characteristics of phytoestrogens and other bioactive compounds, (d) topical and oral clinical studies of bioactive compounds (phytoestrogens) as antiaging treatment(s) for estrogen-deficient skin (during peri- and postmenopause), and (e) the advantages of treating the skin from the outside to inside by traditional topical therapies and treating the skin from the inside to the outside by nutraceutical supplementation, which represents a relatively new innovation of increasing popularity. While this is a growing area of research with promising results, more investigations are needed to understand the mechanism(s) of how combination ingredient formulations work to improve skin health and slow down the advancement of the aging process.