Hi Ady,
I just came across your post (I realise it is from a while ago).
There is a natural alternative to tamoxifen. It is called diindolylmethane or DIM. It is a derived from cruciferous vegetables such as broccoli, brussel sprouts and cauliflower. It is thought to help regulate excess estrogen in the body, reducing the type of estrogen that feeds BC.
However, it is not a scientifically proven therapy. So I wouldn't want to rely on DIM alone to prevent recurrence. It may help, it may be better than nothing but then again we don't really know for sure.
I too was hesitant to take tamoxifen after reading about all the possible side-effects and considered just taking DIM as an alternative. But then I read about a study under way at the University of Arizona into whether taking tamoxifen and DIM together is more effective in preventing recurrence than taking tamoxifen alone.
In the end I didn't want to take the risk of not taking tamoxifen so I have been taking both for the past 3 and bit years. I don't have any major side effects from either substance and so far - touch wood - no recurrence. I do try to do lots of exercise as well, eat a healthy diet with lots of vegetables and I have cut way back on drinking alcohol.
If I were you Ady I would try the tamoxifen first (maybe you already have.) Not everybody has bad side effects from it and at least you know that it is scientifically proven safeguard against recurrence.
If you're interested in the DIM perhaps talk to your oncologist about it. Mine didn't have much to say. She didn't specifically advise against it but she didn't support it either.
My plan is to finish my five years on tamoxifen and continue taking the DIM indefinitely, perhaps for the rest of my life. I order it from a US company called BioResponse Nutrients because that's where the Uni of Arizona source the DIM for their study. I figured it must be okay. It is a little pricey though - about $50 for 2 months supply - but I look at as a bit of extra protection.
Anyway, good luck with everything. Hope you stay well.