Tamoxifen and brain fog


I would love to know if anyone is experiencing brain fog and mental overwhelm whilst on tamoxifen.  I have experienced times when I just can’t make another decision, my mind feels ready to burst.  It leaves me tired, feeling disconnected and spaced out.  

What has anyone done to try and stop this and keep the mind focused. Exercise, yoga and getting outside helps but I can’t do that all day! Any thoughts or recommendations would be really appreciated. I’m keeping an eye on which brand of tamoxifen I’m taking as I’m sure its getting worse, but unfortunately I have been on a lot of different brands over the last year so have’t got into a good pattern with one brand!

Thank you 

Hi Sazzer,

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Sending you our warmest wishes, 


Hi, You are not alone. I have been on Tamoxifen for 4 months. I have been lucky to get RelonChem each time. 

I too have brain fog, I can’t concentrate-have put aside a few books as I can’t get into them.  Memory like a sieve .I just can’t focus.  My conversations are stop start, jumping from one subject to another. I can no longer multitask. The first month I cried a lot, less now. (Several times a week rather than day) I’m prepared to put up with it as I dont have hot flushes or joint pains as some seem to do. I have a walk or do yoga or Pilates most days. I’m planning my allotment. I write things down in a note book -things to do, phone conversations (not family and friends) I try to plan a week a head, 1 thing a day and what I’m going to eat. I feel I don’t have any structure, getting dressed and out the house by 11 is now an achievement!! Acceptance that I may last for 5 years could help, look how quickly the last year has gone.

I hade my op. In July then radiotherapy in September before starting Tamoxifen end of October. I’ve not had a blood test or bone density scan . I was on the pill until diagnosis in June age 52. As this past year with Covid I don’t know what’s the side effects of tamoxifen and what’s the current situation Nothing is ‘normal’