Arimidex - feeling weak


I have been taking Arimidex for 4 years and at times, feel overcome with a real feeling of weakness in my arms and legs. I know this is written on the leaflet as a side effect but I wondered if anyone else had the same overwhelming feeling of weakness as I do?

Sheana x

Hello. I’m on Aromasin but get much the same feelings at times. I’ve been on it for nearly three and a half years.

Best wishes
Anthi x

I’ve been on Femara and Zoladex injections for 2 months, and my worst side effect is a feeling of weak muscles, especially legs, so I understand how you feel.

Thanks for your comments ladies…sometimes the hypochondriac in me kicks in and I imagine all sorts even tho I know weakness is a recognised side effect of Arimidex. I’m glad I’m not alone :slight_smile:


Hi Sheana,
Finding this forum really lifted my spirits. I’ve been on Arimidex for 9 months and the side effects seem to have built up gradually. Feeling weak in the legs is certainly one of them for me, I just want to lie down.I can’t pin down what brings it on. At other times I can walk for miles without drooping. As they say, we are all different.

Hi Eleni,

You describe what I feel…it’s such a weak feeling that I have to stop whatever I’m doing and sit down. It kind of reminds me of feeling faint without the light headedness…really horrible. Other times I am fine so it’s strange isn’t it. Another side effect I have started to get over the last months is a kind of staining on my knickers…sorry! It is light brown but never see anything on the loo paper, just on my pants. Anyway, as usual, the experts are all very vague about it and say not to worry as I had a normal smear etc. I’m not sure how common this is tho.

I think my side effects have got worse over the last year, so that is during Year 3 really. I definitely feel that by September next year when I am due to finish with Arimidex, I will be well and truly ready to stop. I’m not usually a ‘side effect’ person and try not to read any of the leaflets so that I’m not bringing it on myself, but Arimidex definitely affects me.

Still, it’s a good medication so shouldn’t complain.

Sheana x

Hi Sheana Y

Thank you for posting on this subject. I have fatigue and weakness with Arimidex too, but it’s sometimes very difficult to get others to understand, particularly because I often appear perfectly fit.

In fact it has really retricted my mobility - I can’t walk for more than twenty minutes max and if I do anything strenuous like gardening, I can hardly stand up afterwards.

You’re right the longer on the drug, the worse the side effects seem to get. I’ve been on Arimidex for nearly 5 years and can’t wait to come off it later this month though, of course, I am glad to have taken it and survived for 5 years because of it.

Hang on in there - it really is worthwhile!


Hi Ro,

I want to thank you too for posting. I understand what you mean about getting people to understand what you feel like because it’s a feeling that I’ve never experienced before taking Arimidex. It’s horrible.

I am 49yrs old and feel like I’m 90 and it really saddens me that I’m old before my time. When I have asked the BCN’s if I will feel better when I stop taking the medication I get the usual shrug of shoulders and ‘well, some ladies do but we will have to wait and see’.

I know it’s a good drug and has hopefully done it’s job but it’s hard to cope with at times.

I can’t tell you how nice it is to have someone who understand what I feel like.

Sheana x

Hi Sheana

It was good to hear from you too. Like you, I am wondering to what extent I’ll feel better when I come off Arimidex. I expect it will take some time to recover, but I’m not sure.

Feeling old must be difficult because you’re only 49. I’m 57 now - 5 years older than I was when I started on the drug, so it’s difficult to judge how I will feel when I come off it… I’ve become so used to feeling ancient that I’m not sure how much of it is due to the normal aging process and how much is the Arimidex. It will be interesting to find out. I will post and let you know.

All the best, Ro

Thanks for sharing - I’ve been on Arimidex for 2 months now and get so tired so hope it does not get worse - I can walk for 40mins max and then just have to sit down to rest my muscles. It’s a real effort getting out of seats or off the loo too!! Really grateful for handrails wherever I go now…
Glad others have shared their experiences bacause I have bone mets and it’s all too easy to worry about SEs or if mets are growing and hospital are not really monitoring the bone mets. I’m doing lots of work on myself to try to accept this new reality of less energy - hard to keep explaining to others that I need to pace myself and have rests but if I don’t I get an overwhelming weary tiredness so am trying hard to plan in rests on avoid overdoing things on some days as I then feel really weary the next day - takes lots of planning and assertiveness which can feel difficult. Am even thinking we need a vehicle with a bed in it to give us flexibility to go out for days but to allow me somewhere to rest horizonatally since just sitting is not very helpful - anyone tried this idea?
take care
Fran x

I haven’t been on these boards for ages but thought i would look and see if anyone else is as worn out so easily as I am. I have been on arimidex for four years and have suffered from fatigue and weakness since the begining, however I am sure it is worse now or maybe just at the moment. Whatever, I do get fed up with it.
Actually I get fed up with not being able to do what I want to do and most of all sometimes - just sometimes - I get fed up with being grateful that this drug is probably keeping me alive.
Having got that off my lack of chest… in answer to Fran, we have a motorhome and it does mean that we can go away or just out for the day and I can rest as and when I need to because, as you say, just sitting doesn’t do it, we need to lie down. I would be able to do much in the way of travelling without it.
I’m sorry so many of you are feeling so tired and weak but glad it’s not just me.

Hi Nicola,

I am glad that you posted. I understand what you mean by being totally sick of it all…it really is crap. It sounds like we have been on Arimidex for the same amount of time, May 06 was when I started after 6 months on Tamoxifen. I know it’s a great drug but I hate that I have to take it.

It does help a bit to know that we aren’t alone. Keep in touch.

Sheana x

Hi Nicola and all
This site is so helpful! I start to think all this weakness is just in my head but I do know it exists and it’s the strange experience of not being able to make it better that is so frustrating -I’d have hoped that my stamina would get better if I went on longer walks each week but no joy - I just get more tired. So am working on accepting this SE of the Arimidex. Nicola - thanks so much for writing about your motorhome and how it helps - we have been out looking for one as it really does seem like a possible solution to needing to lie down each afternoon and we’ve always enjoying camping (definitely don’t plan to go off in a tent any more!). Is there anyone who knows anyone with a van conversion for 2 people but seating for 3 who has one for sale??? At least we had fun looking in showrooms this weekend - but not much Christmas shopping got done as a result…
Keep positive and hope you are managing the SEs ok

Hi ladies,

I’ve been really struggling with feeling weak over the last few weeks. I can be fine most of the day and then I might get up to wash the dishes or something like that and get the most horrible weak feeling in my arms and legs and feel like I must sit down.

I started this thread and there have been quite a few people on Arimidex with problems of weakness but I’m still curious to know if it’s the same kind of feeling I get?

It’s so hard to explain what it’s like…my head is full of worries again about it, convincing myself that there is something sinister going on.

Sheana x

Hi Sheana.

Sorry for late post, been busy - or what passes for busy these days. I get that weak leg and arm feeling too. I have been on Arimidex for over 4 years and in the early days I would ‘hit the wall’ on a regular basis, at least daily. This would be an overwhelming feeling of total exhaustion which would require me to lie down.
But as the years have passed this happens only rarely now, however I still get worn out very easily. I think it is probably more to do with the fact that I have learnt to live within the bounderires of my strength and energy - if that makes sense - and the acknowledgement that I will never be the same as before so have stopped trying to push past what my body wants to do.
I have tried everthing to get my energy levels up but this is now me and I can live a happier life not trying to wish it different.

Having said all that it is still hard and sometimes scary to get so unreasonably tired. It doesn’t show so unless you know me quite well I look fine. I get fed up with explaining when people suggest doing things I know are beyond me so now I don’t.
It is also hard to push those doubts about why we are so tired and weak out of our minds but my reasoning on that is that it is no worse than last year and I’m not dead yet so…

This is turning into a bit of an essay but what I really want to try to explain is that you are not the only one and it is perfectly reasonable to be scared and worried and depressed - I am too, often. I try to enjoy the enforced rests by reading or watching rubbish TV.

Best wishes.

Hi Sheana, Nicola and all

So am getting ready to pace myself for a trip to town to physio for shoulder replacement and to do some tiny bits of Xmas shopping - so plan is to go on long bus route but it’s closer to walk to at home and return on same bus from stop near to shopping centre (can’t drive at the moment after arm op), have leisurely lunch, shop for half an hour, physio and then return and rest… Feel that I spend my life managing my energy levels - last week in town I “just had to sit down” and had a long sit in the loos as I didn’t want to go in another cafe!! Felt reassured yesterday after excellent “Living with Secondary Breast Cancer” session run by BCC in Sheffield with a focus in the afternoon on “fatigue” to find that many of us have this problem with extreme fatigue - so I must just accept the need to manage energy demands - this often feels selfish as I put my needs first eg. “No we can’t go shopping tonight as I’m feeling too tired - but you can go if you want to.” to husband the other day.
Like you I appear “fine” a lot of the time so it’s clearly hard for family to understand that energy can suddenly disappear and have overwhelming need to sit down. Thank goodness for internet shopping for food etc so I don’t have to shop too often as that really is draining… Will just have to delegate more over Christmas too - probably not a bad thing to do anyway… Still looking into getting a motorhome!!!
Take care - cherish yourselves

ps Really recommend the BCC session on Secondary Breast Cancer if you can get to one and it’s relevant to you - it was worth the effort coping with freezing train stations etc. Lovely to share with others in person like we do on this site. We did a deep relaxation and that really helped energy levels - think it’s better than TV, reading etc as I switched off from my pressures and did not add fictional ones to my life for a while!!

Hello everyone,

I’m new to this thread and was having a look as I’ve been on Arimidix for only 2.5 months but I feel rather old and stiff as some of you have been describing! Its mainly if I sit in one position for any length of time - its then an effort to get up! I’m 56 but this definitely makes me feel older.

I think my energy’s pretty good though - I’m still enjoying the recovery of energy after 7 months of chemo. Even on Arimidex I do feel a lot better!

Its useful to have read everyone’s experiences of this drug. Thank-you. Has anyone found any supplements or anything that help with the stiffness? Any advice from the medics you’ve seen?

Hi all
Just to add, I have had not maybe weakness in the daytime, as I am able (at present) to be on my feet most of the time (at work) but when I get home and do as we all should be able to do - relax- then yes… No more than 20 mins and I have to hold onto furniture to help me stand and I also feel ‘shaky’ - can’t really explain it. After a nights ‘sleep’ the morning geting out of bed is not what I look forward too - weak to say the least. Wobbly and feel like my legs can’t take my body’s weight. In the night when I need to go to the bathroom, the standing on my legs to get there, is worse than geting a disturbed sleep!
Am only into month 4 of Arimedex and would like to to know if this levels out or worsens? Much better than chemo and if it stays par more doable. Concerned about this impact worsening as I have 4+ years of said hormone.

Any input??

Techo x

I’ve been very interested to read all the posts on fatigue/tired limbs etc, having been on Arimidex for just 3 months. When the leaflet mentions “less than one in ten” or “more than one in ten” experiencing various side effects, it doesn’t always mean a great deal. Hearing others’ experiences does help, however.

I do at least seem to have got over feelings of slight nausea by taking the tablet with food. I’m a bit disappointed that my eyebrows seem to have thinned, however, as when they grow back after chemo you hope they will then stay !

Although other people I know have been on Tamoxifen, no-one else has been on Arimidex and lots of people don’t seem to have heard of it. As several others have mentioned, after friends (I don’t have family) dealing with post operative me, chemo me etc it’s hard now mentioning Arimidex me !! Mind you, at times when I struggle to stand up, think they probably are aware !

Hi I too am on Arimidex started it after chemo at the same time I started my RADs, so been on it for around 4 months now.

I find it hard to decide whether its my old age or the Arimidex that gives me my stiff joints and bone pain. I also recognise the weak/tired symptons I certainly am not the girl I was.

I don’t understand the difference between Femera and Arimidex and why the Onc chooses the hormone for you. I know Arimidex has a good reputation and is effective for post menopausal ladies and for me I take my tablet daily with water and know I will have to live with the side effects. A friend of mine said her’s lasted around 4 years so its a long road ahead!.