I have my 6th month check up for hrt on wednesday.  While I have had decent results so far on oral tablets of estradiol, I would like to try injections.  I work at a pharamcy and checked with our vendor and the estradiol valerate shot is still on backorder but the cypionate isn't.  Has anyone used the cypionate and how does it differ from the valerate in effects?  My Dr wanted to start me on valerate but it was not available and didn't mention cypionate.  Thanks.

I take cypionate nowadays (because of the shortage) but I've previously taken valerate, too.

Estradiol Valerate (EV) and Estradiol Cypionate (EC) are two different esters of bioidentical 17b-estradiol; they are "pro-drugs," meaning that the body processes the molecule first, cleaving off the 17b-estradiol molecule from it attendant salt where it then can do its magic.  The cypionate ester differs from the valerate ester in that it generally takes the body longer to perform that "cleaving" -- possibly because cypionate is lipophilic. 

Regardless, what it means is that whereas peak estradiol levels generally occur about two days after injecting EV, serum levels peak in more like 4 days for EC.  The EV peak will be higher than the EC peak, but EV will "drop" quicker as well, getting processed out of the body in about 7-8 days, whereas EC will take 10-11 days to leave the system. 

I've enjoyed both forms, but if anything I like the "smoother ride" of EC; with EV I'd have to inject 4 times a month, whereas with EC it's only 3 times a month.