Scottishgirl, they are not the same, as they contain different oestrogens. Ovestin is a cream containing estriol and you insert a measured dose with an applicator. It can also be applied to the vulva. Vagifem contains estradiol. The procedure for both is the same: 14 days initial load up and then at least twice weekly.
Another vaginal delivery system to consider is the Estring. This is a silicon ring which stays in the vagina for several weeks and delivers a steady dose of estradiol. It is supposed to last for 90 days, although I find it runs out of steam a bit towards the end of its life.
JP x