Estradiol vs. Estradiol Valerate

What's the difference between estradiol valerate and "normal" estradiol?  What different effects/side effects does estradiol valerate have compared to estradiol with no valerate?

[Machelle Seibel, MD]

Estradiol is the main estrogen produced from the ovaries. It is an 18 carbon chain. Sometimes another substance is attached to the "alkyl" group at carbon 3 to allow for different forms of administering the estrogen such as injectable versus oral. The valerate that I'm familiar with is an injectable estrogen. That would make it last longer than "normal" estradiol. But estrogen is estrogen. In comparable dosages, the effects and risks and benefits would be the same.
Machelle M. Seibel, MD