Letrozole and anxiety/depression

Hi all

I’m wondering if anyone else suffered mental health issues on Letrozole.

I’ve been on it since Jan 21 (surgery March radiotherapy May) and had not suffered the usual joint pain or other common issues - however, my mood became progressively worse ( which I had been putting down to diagnosis etc) to the point that I was crying in the middle of speaking, feeling so low, suffering anxiety - when I saw my Oncologist for follow up last week (just sat crying) he told me to stop Letrozole!! For review in a month with aim of changing to Tamoxifen (I’m post menopausal).

1: I’m worried about being on nothing for a month even though he is not concerned and says it’s fine!

2: I’m wondering if I’d have been better staying on Letrozole but with fluoxetine antidepressant on top (I’ve had this in past) …………Has anyone got experience of antidepressants helping with severe low mood on Letrozole?? I haven’t seen anyone else experiencing just this one side effect on here. I feel so much better within a few days of stopping but am

not keen to change to anything else as they all have such bad side effects. I need to get my life back and return to work etc but having to now start on something new is do daunting.

thanks Xx

I take fluoxetine for MH problems been taking it for several years.
I am also on letrozole so when I was told this could cause depression I was very concerned.
A month into letrozole I did notice my moods were heavier and darker (not like the normal way I was used to feeling) I decided as I had only been on them for a month to see how it went.
I did get leg and joint pains which really floored me and knocked me off my stride.
To cut a long story short, the mood pattern did change, they sort of went back to pre letrozole so I now take both the antidepressant of which I did take together first thing in the morning.

I changed over to taking letrozole in the evening at about 9.00 to see if it would help the muscle pains during the day (and yes it has) no change in my mood pattern things remained as stable as possible for a person being on medication.

I think (and it is only a thought) my downward mood spiral was due to months and months of treatment, being tired, scared you name it we do go through an awful lot (I also truly believe my anti-depressants helped me cope with a lot of that and I managed to stay calm.

This is only my experience and would not want to make any suggestions - this just to let you know what my experience with Fluoxetine and Letrozole has been like over the past 5 months.
Good Luck with it all I hope you find your answers.

Poppy xx


i was already prescribed citalapram before starting letrozole…can’t say I have noticed any difference in my mood since starting.   I previously took tamoxifen but developed a BC in the other breast so don’t think tamoxifen really worked for me…I’m post menopausal now so letrozole if the way forward I’ve been told…just have to hope it works better for me than lterozole

wishing you the best … and hope tamoxifen works out for you 

I experienced severe anxiety after only 3 weeks and stopped. Interested in how you went and if you added anti depressants? Hoping you are ok 

Hello, I’m sorry to see that you are struggling with Letrozole. I was prescribed it also and felt so bad, joint/leg pains and very low moods that my oncologist changed it to Anastrozol. I’m afraid that it doesn’t seem much better at all. I’m in the same situation as you. I feel anxious and depressed. I’ve considered going onto fluoxetine too. I have a telephone consultation with my GP in two weeks time. I’m going to discuss that with her. I also find it difficult sleeping and have a constant headache. Sometimes I wonder if having to go through all this for five years is worth it! I’ve been on it since Jan 21 too. 
I will post to you again when I’ve spoken to my GP. Best wishes to you x 

just reading the posts and sounds like we are all the same boat here.  I was on anastrazole and sertaline, then exemestane and sertaline now exemestane and fluoxetine. I’ve never felts do low and anxious  and I had anxiety depression for over 20 years. Im at the point of giving up work due this and the fatigue plus menopause. I wish I had the answers. Another 5 years on this is daunting xxx


I have been on Letrozole for three years, it effects sleep and anxiety.   I have started Zoloft but I am not really depressed but anxiety is bad.   I feel weird  I have hair loss from med too.  I can get angry quickly…  I am not sure Zoloft is the best med for me, but I do know I will have to take something.  You are not alone when it comes to mental issues coming with Letrozole.  I have been on it for three years.  I just moved to Minnesota to be close to my daughter so I am adjusting to that as well.  I have also started taking Prolia injections for my bones. Who knows maybe I need to take a break.