Different brands, affect everyone differently. My wife was initially on Letrozole, and didn't tolerate it well at all. The doctor tried her on other brands, each with varying degrees of side effects.  She stopped taking it, and after talking with her oncologist, she was put back on Tamoxifen. My wife is in a weird place with all of this. She's now 54, but because she had some thickening of the womb, whilst they were taking biopsies to rule out the sinister stuff (luckily, it was all benign), they took samples to see if she was pre or post menopause. Her cells came back as pre, but only just. They suspect she is post, and the results came back that way because sometimes they do, but because she couldn't tolerate Letrozole she was just put back on tamoxifen because she has breezed through that medication thus far.

But the long and the short of it all is, your side effect to each brand will be a highly individual thing.

Different brands, affect everyone differently. My wife was initially on Letrozole, and didn't tolerate it well at all. The doctor tried her on other brands, each with varying degrees of side effects.  She stopped taking it, and after talking with her oncologist, she was put back on Tamoxifen. My wife is in a weird place with all of this. She's now 54, but because she had some thickening of the womb, whilst they were taking biopsies to rule out the sinister stuff (luckily, it was all benign), they took samples to see if she was pre or post menopause. Her cells came back as pre, but only just. They suspect she is post, and the results came back that way because sometimes they do, but because she couldn't tolerate Letrozole she was just put back on tamoxifen because she has breezed through that medication thus far.

But the long and the short of it all is, your side effect to each brand will be a highly individual thing.

Thank you for the information concerning your wife. I am 81 and have had surgery for breast cancer and the removal of my axillary lymph nodes (of which 4 were cancerous). I understand that for someone whose cancer has spread Letrozole is the preferred treatment alongside radiotherapy which I shall start in two weeks' time. If after a few months I am still experiencing side effects I shall pursue the matter with my oncologist. With all these powerful drugs having different risk factors - bone deterioration or possible blood clots - I think it is probably "Hobson's choice"!