Tamoxifen half strength effectiveness?

Thanks all for replies to me.  TonyaM your reply was of particularly relevance for me.  Very interesting about the liver connection. Of even greater interest for me was to hear about the Endep. Sadly post surgery (lumpectomy, reduction and re-constructionn all at same time) I developed extreme nerve pain in both breasts. Hurt to breathe, car rides were a nightmare all those speed bumps etc. Went to a pain specialist and he suggested Endep for the nerve pain, didnt realise it was an antidepressant as well. I have been on 5mg Endep post surgery for about 8 weeks now. I am leading up slowly to taking the full dose of Tamoxifen. On 10mg every day now, trying to get to the 20mg. The hot flushes are manageable, about 10 in a 24 hour period but the insomnia is really impacting even with the Endep. As you can imagine quite worried about symptoms increasing once I am on 20 mg, hence my question about 10 mg being effective at all? I have been told by my Oncs (one radio Onc, one medical Onc) that post surgery chance of re-occurence 10 years is down to 10-15%. Post radio it is now down to 5%. with Tam it is down to 2-3%. Makes me wonder if the extra 2-3 % is worth it if my quality of life on Tam its compromised. I want to give it a very good try however. Oh and btw, nerve pain has settled to bearable now but suspect it will be with me for a long time. Endep may be my long term friend!