Tamoxifen and muscle twitches

Hi. Anyone suffer from muscle twitches whilst on Tamoxifen? Mine are still very infrequent but are getting more frequent. They are like a very small involuntary twitch of a muscle. I had my operation last year, radiotherapy but no chemo and have been on Tamoxifen for nearly a year.I suffer lots of hot sweats so I know my body not happy on Taxoxifen. I see specialist next week so will be discussing.


Just saw your post. I get what I call a muscle spasm in my back, don’t know whether its the tamoxifen(been on it 5 years, now about to change to fermar) but it could be. It usually happens when I’m tired and I have had it on & off for a while.


Hi there

i’ve been on tamoxifen for 6 months now and have had a whole host of minor side-effects. I had about 3 weeks of terrible cramp in my legs and feet but only at night. At the same time but during the day I noticed that I had a lot of muscle twitching in my legs. I only realised that was what it was as I thought my mobile kept vibrating but not ringing ( I carry it in my trouser pocket) but then realised it was my muscles twitching. After about 3 weeks the twitching stopped but still get the odd cramp in my feet. I don’t know if the twitching caused the cramps or not,

Hi there, My experience of Tamoxifen was terrible. I took it for nearly 4 weeks and am now having 10 day break to see if it is cause of side effects. Feeling more myself after 9 days without depression muscle, joint and teeth pain (had a major foot op in oct just before diagnosed with bc and Tam makes surgery bone repair worse), also extreme tiredness, hot sweats not being able to cope with easy tasks and nausea. Have been told there is no alternative so dreading next 5 years. How does anyone else cope with these side effects?
Don’t know about anyone else but the mastectomy (2 ops) and radiotherapy wern’t as trying. Will be seeing a homeopathic dr soon which may be able to help as think that should not take any supplements as cancer oestrogen positive. I live in Farnce and although treatment been very good there is not alot of support after with someone to ask.

Hi sandraann52
Just picked up this thread. I am like you, I have been on Tamoxifen for 1 yr I still suffer from very bad hot sweats, I had my op last year and had radiotherapy which finished last December. I have just started (last month) with the muscle twitching and its driving me mad - what was the outcome of your chat with the specialist before I call mine - I am worried sick, but glad I looked on here. They don’t tell you that you might get these side effects do they? Do you still have yours, did they change your meds? I keep thinking something else is growing inside of me, I have them at the top of my ribs, my eye, leg, stomach but mostly at the top of my rib cage, hence the worry.
Any help or advice appreciated.

I have been on tamoxifen for about 1 year and recently, (about 2-3 months ago) I started suffering muscle twitching. It is 95% in my calves, though can happen anywhere. It is really driving me crazy and seems like a very weird symptom. It starts as soon as I sit or lie down,disappears completely when I am active. I don’t know whether to call my oncologist about it. My PCP blew me off, saying “drink more water”. I know it is not that. Found this thread and wonder if anyone has had this and had it go away if they stopped the tamoxifen.
Thanks for any help!

I have been on tamoxifen for a week now and have been have the twitching in my leg and foot. I asked the oncologist today but he didn’t seem to think it’s connected with tamoxifen, but it started after taking it, I am also really tired and having lots of hot flushes. 

Charys your GP sounds fab. And how reassuring to have such a thorough check. My twitches are a little better but I felt so rubbish on Friday after being on it for 10 days. I felt just felt so unwell I couldn’t move and felt in a mental fog.  I decided it was the tamoxifen and I didn’t take it Friday night. Saturday I felt like old me again. I have started to cut the tablets in two and have half morning and night. I am so so tired on it and still having loads of hot flushes. I have just ordered a cool sleep pillow from Amazon which was recommended by a friend. I thougt my fan had broken just now and was feeling really panicky at the thought of a night without it. 

Well, for anyone reading back this thread in the future, my oncologist says she has ‘not come across this before and doesn’t think it is serious and suggests I continue with the tablets’. I don’t understand why oncologists aren’t coming across this  muscle twitching thing, there is so much annecdotal evidence, admittedly not that commonly, of muscle spasms and involuntary movement/twitches. Oh well…onwards and upwards…

Hi all. I’m late to this Tamoxifen “party” but I have been on it for about a month…after trying a couple of other meds…I have had horrible joint pains and since I’ve started the Tamoxifen, I have random favial twitches!! So annoying and quite worrisome. I’m exhausted and super emotional…I suppose after what I’ve gone through in the past 9 months that’s to be expected but I have to be on this for FIVE years and am hoping these side effects subside…