I don't believe your gyn. I've heard too many different numbers about the equivalents, 5 times 10 times 100 times. I don't know what to believe. Ive even heard this: "The effect of EE relative to estradiol differs in different tissues. In the pituitary, it is about 120 times more potent, in the liver 500-1500 more potent." maybe it has some aevantages over 17b and maybe 17b has some advantages over it as well. I dont think it can accurately be converted to equivalency. its technically a different molecule. what? how?