Letrozole or Arimidex?

I have another appointment with my oncologist to discuss which hormone treatment I should have. I am 55 and, assume, post-menopausal. I was on HRT for a long time and the onc decided to wait before starting the tablets, to let my hormones settle. She was going to start them at the same time as the rads, but I have now found out that won’t be until mid-December (12 weeks after my surgery - another thing I am worried about).

Anyway, I don’t want to wait that long, so she has agreed to start me sooner. She doesn’t seem to have decided about what to give me, even discussed Tamoxifen, which I didn’t think was as good as an AI for post-menopausal women, so I am thinking maybe I should try and influence her to what I/we think would be best!

Any thoughts - pros/cons - would be appreciated. Thanks.

Ann x

Hi Ann

I’m 57, and can’t comment on Arimidex only Femara. I’ve been taking it since last Christmas and have found the SE to be minimal. Aching thumbs first thing in the morning and that’s all. I know that a lot of women on this site have more difficult SE but I think that only those having problems tend to post. Those like me don’t bother.

People’s reactions to the drugs are all different and it’s a matter of finding one that suits you.

Good luck


While I think in most respect these forums are great, I sometimes think when reading peoples experience we worry about things that will probably not happen. I have been taking letrozole for 3 months with no side effects to speak of but reading some experiences I find I am waiting for my hair to fall out and my legs to seize up.

If I had not read any of the posts I would not have given side effects a second thought. If you read the side effects leaflet in a packet of paracetamol its scarey.

Hope I am not speaking too soon, if I am will keep you updated.

Best wishes.


Hi Ann
I am 51 and started on Arimidex 8 weeks after my surgery, through choice due to plans made before I was diagnosed. I have been on it for 6 weeks so far and apart from tiredness and a cotton wool brain I do not seem to be suffering too badly (touch wood). From what I can make out, many of the side effects for arimidex are ones that some of us (me included) get during the menopause and these tablets have the same effect as the menopause by reducing oestrogen. I was worried that the tablets would make the symptoms come back, but to date it seems ok.
If you have been through a natural as opposed to surgical menopause I have read somehwere on this site, that the symptoms of Arimidex are not likely to be so much of a problem.

Not sure if this has helped, but good luck anyway in your choice.
I think I found the choice of treatment the hardest part overall due to my lack of ‘expertise’ in this area!

Apologies for the ramble

Thanks, ladies. Having come off HRT when diagnosed, I am already experiencing the menopausal symptoms, but not too badly. I do have problems with sleep, in that I wake several times a night, and do have slight hot flushes, but not sweats as such.

My thoughts were more about the effectiveness of either drug, and how the decision was made about which you should try, as they are not the same. Were you given a choice? Were both drugs discussed?

I don’t understand why the oncologist would think that Tamoxifen would be suitable for a post-menopausal woman, when the ovaries have stopped producing oestrogen and studies show that an AI works better.

My appointment is this afternoon and I am still confused.

Ann x

I was not given a choice, good job as I am hopeless at making decisions.

I am 62 so maybe that has a bearing on any side effects, I probably haven’t much estrogen in my body anyway.

Good luck.


Hi Ann

At 62 I am definately post menopausal and was told by my Onc that I was to start with Letrozole because she considered it to be the best for me. However she also said that if the SE’s were too bad she could and would move me to a different AI.

I have been on them now since June and have some SE’s but nothing that I can’t live with. I take evening primrose oil daily and that seems to deal with the majority of the hot flushes and sleep disturbance and I also make sure that I have a glass or two of tonic water or Bitter lemon daily which deals with the cramp that I expereinced at the beginning. Someone else on this thread has mentioned problems with their thumbs first thing - I get that as well but it has worn off by the time I have dealt with breakfast and the morning chaos getting OH off to work.

Hope you get it sorted out and reach a decision that you are happy with


Hi they are very, very similar A.I.'s . The side effects from both are also similar. Aromasin works slightly differently again. I hope whichever one you have works well for you…x

Thanks, ladies. All thoughts gratefully received. I want to be as forearmed as possible this afternoon.

Ann x

I saw a lovely Spanish locum oncologist this afternoon. Basically, he let me choose and after some discussion, I decided to try Letrozole. By then though, the pharmacy was closed and I have to go back to get the tablets.

My reasoning was that, according to the surgeon I saw recently, the hospital uses it a lot and as it is not the cheapest (and so that is not why they use it), I decided there must be a good reason and so went with that one. Well, that was my logic, anyway. Thanks for your help, ladies.

Ann x

Well, I have started taking the Letrozole today but reading the list of possible side effects is really scary. No wonder they say I have as much chance of dying of something other than bc within the next 10 years!


HI Ann, Good luck with Femara. I started this in July and have only experienced mild side effects - for the first few weeks my hair went very lank and lifeless but recovered and is back to normal now. I do have the occasional ‘heat wave’ during the day and have had a couple of nights where I have woken up absolutely sweating uncomfortably but an odd night is something I (and I guess most of us) can cope with.
Reading the manufacturer’s information on side effects can be scary and most of the things listed are rarities but we need to be aware that serious things can happen so that we don’t ignore any major changes we feel in ourselves.
I would suggest that now you know what could happen, be aware of this but otherwise just carry on concentrating on the here and now and note any changes you experience without getting too alarmed about them.

Hi Ann
I started taking Letrozole on Saturday. I’ve had nearly tow years on Tamoxifen but the brand I was taking has been discontinued and so I’ve been put on Femara.
The leaflet in the pack says that any side effects should wear off within a few days. I felt sick opn Saturday and Sunday morning but that’s gone now. My joints are a bit stiff and I’m getting really tired so that I can’t keep my eyes open but I’m OK apart from that.
I do hope you don’t have any probs.
It would be good to compare notes.
Jan xx

Interesting to hear about your hair Hattie, I have been taking Fermara for 3 months and I’ve noticed my hair is not in very good condition, I have just finished rads so maybe its a combinaton of the two.

When I mentioned feeling sick, I was told to drink water and it does help.

Good luck everyone.


Hi All. I am will be starting Letrozole after my rads which should be December/January. Could not be on tamoxifen as i got a blood clot at the beginning of treatment. I have heard that bones and joints are really painful. Would love to know how you all get on with it. xx

Yes, Jan, I shall be interested to know how you get on, and I’ll keep you posted. I have been having some symptoms due to stopping HRT, so I don’t know if the tablets will make them worse.

It also helps to know how others are doing, who have been Letrozole a while.

Good luck all. Ann x

Hi Anne,Im 57,been on Letrozole since June,have had good and bad SEs,my hair has never been thicker but Ive got lots of aches & pains. Im always tense and anxious which may or may not be linked,Bachs flower remedy squirted on the tongue really helps with anxiety,a pharmacist put me onto that. I have good and bad days with my appetite,at least Im not putting weight on.Anne,do you live in Spain,I am planning to live there in the next 12 months and have been told Letrozole costs 168euros a month,can you comment?
Cheerio,love Mags x


Which Bach’s flower remedy do you use? There are lots - or do you mean Rescue Remedy.

No, I don’t live in Spain. I just happened to have a locum oncologist this week who is from Spain. BarbaraAnn lives in Spain. She may be able to answer your question.


Hi Anne,sorry I didnt reply till now,youre right,it is the one you said,Rescue remedy,2 squirts on the tongue and you can really feel yourself calming down. Ive actually not needed it for a couple of weeks,Ive got constant pain under my armpit,think the surgeon sewed a piece of splintered wood in there,got some new pills for nerve pain (Lyreco),I am now serenely calm at all times,the enclosed leaflet said they are also used to treat GAD(general anxiety disorder). Theres the answer. Cheerio, Love mags x P.S.The Irish(hilarious)authoress,Marion Keyes,mentions Bachs
rescue remedy in her novels.


There is also a Rescue Night Remedy. Not sure if it works, as I am still waking up several times. I have also tried some Boots homeopathic Insomnia Tablets. I do feel they make me sleepy but that is not the problem. It is staying asleep that I have trouble with.

You made me laugh about the wood splinter. Ooh, it sounds painful. Maybe, he just stitched you up too tight. How long since your op? Perhaps it will be better when the stitches dissolve which, according to which website you read, is anything from 2 weeks to 6 months!!!

I have just been to the doctors to get my Letrozole prescription set up and he has also given me Adcal-D3. Reading the blurb, it says that it contains soya, which I was trying to avoid, but it is a very small amount and it is in lots of foods, like bread, anyway so I suppose it is inevitable I will be having some.

Jan - How are the symptoms? I have had a pain down the side of my wrist/hand since yesterday and am not sure if it is the Femara or an extension of the cording, which seems to have disappeared further up my arm. Still have the tingling legs, tinnitus, waking in the night, but these things started before I took the tablets, so are probably a result of stopping HRT, but the Femara may make them worse. I also keep getting a pain in my head above my left ear. What’s that about, I wonder? I have changed from being a normal, healthy person into a bag of symptoms!

Hope everyone else ok. Love Ann x