I've been on Femara for almost 4 years and have tolerated it very well. A woman I work with has also been on Femara for about 5 years and no problems. I understand, however, that Femara and Arimedex are from the same class of drugs so if you experienced side effects from Arimedex, most likely you will also with Femara. Tamoxifen is in a different class, I understand it is not as effective as the newer drugs but it was the gold standard for years so if it were between not taking anything at all and taking something that I could tolerate like Tamoxifen, I would definitely try it or some other class of drug approved for estrogen/progesterone positive BC. Not only do these drugs help to keep a local recurrence at bay but also any recurrence from taking hold in you body. Breast cancer like many other cancers like to send out seeds that just wait for the proper conditions to take effect to allow them to surface. I believe these drugs help to prevent this from occurring.