Declining tamoxifen

When I was told that my breast cancer was homrone-receptive and I would have to go on tamoxifen, I didn't hesitate. If it was going to help prevent the cancer from returning, that is what I wanted to be on.
I have heard that some people decline it, or other start it and then stop taking it and in another post I wrote based on a New York Times article, a reader responded that it turned her into a monster, but when I queried what she meant, she didn't answer - maybe she never read it.
Nevertheless, was rather surprised when a friend of mine - who had a lumpectomy and then radiation - sent me a message saying: "I was also supposed to go on tamoxifen but decided not to. I am now taking a natural remedy called Green Vibrance which is suppose to work wonders, builds up your immune system and many other things".
I am still waiting for her response as to why she has declined to take it - the side effects/someone talked her out of it? but I cannot stop thinking about it.
Look, I am fed up about the weight gain. At the moment 6kg up from my pre-diagnosed (is there such a word?)weight, ie, from my weight before I was diagnosed with cancer last January. Most of the weight I have gained in the last two months. Well the final 2kg which have just thrown me over the edge, as it were. Oh there are other niggly effects, but wouldn't consider not taking tamoxifen. Don't want the cancer back.