I am a male breast cancer survivor. I had stage 1, with surgery, chemo and now Tamoxifen.
Started with 20 mg of Tamoxifen, experienced daily menopause type issues, chills, drowsiness while working full time. Spoke with my oncology team recently, reduced to 10 mg, no longer have daily issues but still get drowsy around noon. My team did not suggest 5 mg due to my oncotype dx score.

I have coffee in the morning, then green tea with some caffeine. At night drink chamomile tea. These are remedies suggested my oncology team to best manage side effects.