I just started Tamoxofin this week. Did your Onco mention a time frame as to when side effects start. I already feel I’m gaining weight but it’s because I can’t exercise until I’m healed. I typically workout an hour a day and haven’t exercised in over a month. Now adding Tamoxifin I’m pretty concerned about my shape.

There are situations in which a patient does better on tamoxifen (a SERM) or an aromatase inhibitor. And vice versa. And there are a few different aromatase inhibitors and, if one triggers uncomfortable side effects, another might be easier to deal with. If you find that you don't tolerate tamoxifen well, consider getting a second opinion if your oncologist balks at exploring the options further.