Epiestriol () (brand names Actriol, Arcagynil, Klimadoral), or epioestriol (), also known as 16ò-epiestriol or simply 16-epiestriol, as well as 16ò-hydroxy-17ò-estradiol, is a minor and weak endogenous estrogen, and the 16ò-epimer of estriol (which is 16ñ-hydroxy-17ò-estradiol). Epiestriol is (or has previously been) used clinically in the treatment of acne. In addition to its estrogenic actions, epiestriol has been found to possess significant anti-inflammatory properties without glycogenic activity or immunosuppressive effects, an interesting finding that is in contrast to conventional anti-inflammatory steroids such as hydrocortisone (a glucocorticoid).