You don't say how long you have been on Tamoxifen but,yes it is a well-known side effect.It may pass if you haven't been on it long when your body gets used to it. All these drugs do have side effects. I am not taking Tamoxifen but am taking Arimidex and have terrible aches and pains in my joints. I just try and ignore it though it does get me down at times - it grinds me down.
