I took Tamoxifin for 2 1/2 years and then Arimidex. My muscle and joint pain got worse and worse until I could hardly walk. My muscles started collapsing so I finally quite after a year and a half. I stopped in March in 2007 and I have improved quite a bit. I can walk 3 miles but my muscles still hurt and I am very stiff. I wonder if I should be doing something to help myself. I am worried that this remaining pain is going to be permanent.