Insomnia from Letrozole

Have been on Letrozole for 6 months and I’ve never been the best sleeper.

In the last 10 days I can’t even get to sleep so end up taking sleeping tablets or antihistamines to knock me out!

I can’t continue like this, any suggestions.

I do all the sleep hygiene things, take magnesium, do yoga/relaxation, don’t drink alcohol in evening etc.

Anyone else experienced sleep problems with Letrozole?

It seems to have progressively got worse.

Thanks for your help

Hi Jippy,

We’re sorry to read you’re having trouble sleeping. This must be very difficult for you. You can speak to one of our clinical nurse specialists who can offer support and information about Letrozole and it’s side effects. You can call them freephone on 0808 800 6000

Sending you our best wishes,


Hi Jippy

i have just joined this forum, I am on letrozole since April, I wake so many times in the night, each time I wake I feel I have to go to the bathroom, I am so stiff when I get out of bed, I really feel like I am 50 years older, I thought it might have eased but seems to be getting worse. How are you now, do you do anything to help you sleep better . Thank you 

Hi Maygirl

I’ve been taking Letrozole for 7 months now and it’s reassuring to read of others experiences. 

I have no trouble dropping off to sleep but wake 2-3 hours later, with pain in my feet and hands which prevents me going back to sleep. I take a couple of paracetamol which help a bit (eventually). I have some peripheral neuropathy in feet and hands from chemo 2 years ago but Letrozole has made pain worse. I haven’t discussed this with my consultant or GP yet as otherwise Letrozole is suiting me. However, I’m sure just 4 hours or so sleep per night is not good for my general health!

I’m reluctant to take sleeping tablet but would like to hear of ones people have had good experiences with  



i just wanted to say hi and thank you for your post. I thought that I was going mad with so many problems with sleep. I’ve been on letrozole for a year now and my sleep has been disturbed for most of the year.

After reading your post and the replies I remembered that I was told to take it in the evening in case it made me drowsy! I have since swapped it to the morning and OH MY GOD!!! I have actually had improved sleep over the past 5-7 days. It’s not perfect but it’s SIGNIFICANTLY better. So I wanted to write in case it made a difference to others. Liz

I have had such a similar response to Letrozole. One difference: I always slept well; I could nap in the day and sleep 8 hours that night. Now I’m an insomniac, waking at 2, 3 or 4  – one time I was awake from 12:30 onward.

I take vitamin D, magnesium and zinc with Letrozole, usually at night because, and this is ironic, I felt so tired and dragging during the day when I took the pill in the morning. Nothing worked. I tried melatonin, Valerian (pill and tea form), melatonin and Valerian in the same pill, antihistamines (be careful, Benadryl is extremely addictive). Each would work for about 5 days, then lose effectiveness. 

I’m constantly trying something different with no long term solution yet. Still looking…

My initial pill was anastrazole and I had insomnia 5 days out of 7

Swapped to exemestane for many side effects and it was about 3 out of 7

Tamoxifen didn’t make any difference

now on letrozole and it’s 2 nights out of 7  and if something wakes me as I am dropping off that is me for a few hours, wide awake.

What I do is take my Kindle to bed under the pillow - then I can read without putting the light on and waking himself who is usually snoring fit to bust (see waking above) - at least I can stay snuggled in bed and have something to do. 

The other trick I have is ‘writing a novel’ in my head - I get  couple of chapters in and by about 3-4 am I am nodding! One day I might put pen to paper!!