Hi Ellie, if you are not going to take any more aromatase inhibitors - and I can't say I blame you - or tamoxifen, you might like to consider a "natural" alternative called diindolylmethane or DIM. It is similar to indole-3-carbonol that Maria mentioned but from what I have read is better absorbed by the body. I actaully tried I3C early on and found it made me a little dizzy.
I did quite a lot of online research on this substance thinking it might be an alternative to tamoxifen. In my research I came across a study being done at the University of Arizona on women with early breast cancer taking both tamoxifen and DIM in a study to see whether when used to together they reduce the chance of recurrance more than tamoxifen alone. So I have opted to do that as well. I figure if women are being given the product in a university study it must be okay.
The product I take is called Breast Balance as it contains some other nutrients that are often deficient in women with breast cancer - selenium, iodine and vitamin D as well as150mg of DIM. I order it online from a US company called BioResponse Nutrients (which is where the Uni of Arizona are sourcing the DIM used by its study participants.)
I have mentioned to my oncologist that I am taking this product and she claims to know nothing about DIM and basically did not want to enter in a discussion about it at all. But neither did she warn me against taking it. She said something along the lines of "it's up to you". She is very reluctant to enter into any discussions about nutrition beyond "eat a healthy diet with lots of fruit and vegies". I think she sees it as a waste of her very valuable time. Had she expressed opposition or serious concerns about me taking it I wouldn't be doing it.
Personally I feel safer taking my tamoxifen as well but if you aren't going to take that or AIs then DIM might be better than nothing. Good luck. Janet.