17α-Estradiol

hormone · endocrine · integumentary · immune-hematologic · Oral · Transdermal

17α-Estradiol, a hormone. 17α-epimer of estradiol — non-feminizing isomer with ~100× lower ER affinity but extended-lifespan effect in male mice… Oral half-life 13 h.

17α-epimer of estradiol — non-feminizing isomer with ~100× lower ER affinity but extended-lifespan effect in male mice (NIH ITP, 2017). Mechanism distinct from feminizing estrogens; possibly via metabolic / inflammatory pathways. Topical formulation marketed in EU for androgenetic alopecia (Pantostin).