Yes estring contains Estradiol and yes it is stronger than the available Vagifem (10 mcg) as from memory I think Estring releases 7.5 mcg per day of estradiol so is comparable to the old 25 mcg Vagifem in terms of weekly dose (if they can be compared). It might in practice even be stronger than the 25 mcg Vagifem (twice weekly) because that is the total contained in the Vagifem pessary whereas in the Estring this is the actual release rate.
I can't comment on the Ovestin because as explained on another thread today Ovestin contains estriol. The dosage was worked out to be the equivalent effect to Vagifem but not sure now whether the research compared the effect to 10 mcg Vagifen or 25 mcg Vagifem..... I'm sure it's on the web somewhere...
Hurdity x
