This information is posted on Dr. Hertoghe's website:
There is some hesitancy among physicians to give estrone, because a few reports have suggested that estrone could be carcinogenic. Estriol, on the contrary, has better press .Many voices say estrogen should be added to every female hormone treatment because several, but not all, studies have reported it to produce protective effects against breast cancer. If a physician decides with his female patient for estriol supplementation, the best way seems not to take estriol transdermally as it is hardly or not absorbed through the skin, but orally or vaginally. My experience is with the oral form. It is in this form hardly, if ever metabolized in the liver. The average dose is 2 mg/day. Estriol should be given the same days of the menstrual cycle or month as the estradiol gel. Never give estriol alone as one study showed that it may highly increase the risk of endometrial cancer if no progesterone is supplied.
However, in his book, The Hormone Solution, he says oral estrogen should be avoided as that puts too much stress on the liver, and that estrogen should be taken either as a cream, patches, or vaginally. Of course, that book was written more than a decade ago, and things change...I have been on E cream (Oestrogel) for several years, take the maximum prescribe dosage (two pumps a day applied on thighs or abdomen), but cannot say it's done much for me...I wonder if oral estrogen would be preferable...? Has anyone here successfully taken estrogen? If so, how (cream, patches, pills...)?