α-Estradiol (17α-estradiol) is a stereoisomer of estradiol with weaker systemic estrogenic activity compared to the β-isomer. It is primarily utilized in topical dermatological applications, such as treatments for androgenetic alopecia (pattern hair loss), where it helps inhibit 5α-reductase and reduce scalp dihydrotestosterone levels to promote hair growth. Unlike β-estradiol, it is not commonly used for systemic hormone replacement therapy (HRT) due to its lower potency. In cosmetics, α-Estradiol is incorporated into anti-aging skincare formulations to enhance skin elasticity, hydration, and reduce signs of aging. It also serves as a research tool in studies exploring estrogen receptor modulation, neuroprotection, and effects on physiological processes.