Topical estrogen therapy for aging skin: Current evidence and clinical considerations

Estrogen exerts well-documented effects on skin structure and repair, making it an appealing candidate for antiaging therapy. The use of prescription cosmetic and off-label topical estrogen creams (0.3% estriol, 0.01% estradiol) has grown rapidly in recent years despite limited clinical evidence, though broader adoption remains constrained by safety concerns. Unlike prior reviews that extrapolate from systemic (hormone replacement therapy) data, this focused review critically examines clinical, histological, and mechanistic studies of natural topical estrogens to directly assess their therapeutic potential. Evidence from small clinical trials demonstrates collagen stimulation, epidermal thickening, and fibroblast activation, supported by findings of increased procollagen and transforming growth factor-β1 signaling with suppression of collagen-degrading enzymes. Increases in elastin density and dermal vascularity have also been reported, though results are inconsistent. Importantly, studies suggest that these regenerative effects may be attenuated in photoaged skin, likely due to UV-induced fibroblast dysfunction. Despite encouraging histological changes, clinical endpoints remain inconclusive. Few controlled trials report visible or patient-perceived improvements, and results vary by site and methodology. Safety data indicate minimal adverse effects, yet systemic absorption and hormonal activity have been observed. With the rising use of topical estrogens, cautious interpretation of their benefits is warranted until larger, independent trials establish efficacy and long-term safety.