Estrogen patches

Estraderm TTS I'm assuming these are the standard Estrogen patches. The base ingredient is Estradiol, a form of estrogen. In this country, estrogen is used sometimes in standard cycles to build up the uterine lining. It's also used for donor egg/embryo cycles to enhance the lining of the recipient prior to transfer. Shouldn't see much in the way of side effects from these. It's more common here, though, to use oral tablets rather than the patches. I'm not sure why.