Pharmacodynamics<unk>  (top) and 17β-estradiol (bottom).<unk>  (17α-estradiol) is distinguished from estradiol (17β-estradiol), the predominant sex hormone in females, only by the stereochemistry of the carbon atom 17. In contrast to 17β-estradiol, 17α-estradiol, while it still binds to the estrogen receptor, has less or no feminizing estrogenic activity depending on its dosage and the tissue it is affecting.<unk>  acts as an inhibitor of the enzyme 5α-reductase, which is responsible for the activation of testosterone to dihydrotestosterone, and which plays a role in regulating hair growth. 17α-Estradiol has been studied as a therapeutic with potential to treat Alzheimer's and Parkinson's disease and other patients suffering from neurodegenerative diseases. 17α-Estradiol (as the sodium salt of its sulfated form) is a minor component (10 μM).
Alfatradiol
Estradiol acetate
Estradiol valerate
Estradiol furoate
Estradiol 
Estradiol
Estradiol diundecylate
Estradiol sulfate