Is there always hair loss with Letrozole?

Hi. I know there’s been quite a lot about Letrozole in general but can I just ask a specific question please. Has everyone on Letrozole experienced hair loss or thinning or is it fairly rare?

Just briefly, I have lobular cancer, had a mastectomy and axillary clearance. Just waiting for radiotherapy and oncologist wants me to start Letrozole now. I thought it would start after radiotherapy so wasn’t prepared for it when he prescribed it today. My hair is just starting to grow back and I’m so looking forward to ditching the scarves and wigs. Will Letrozole put an end to that? Thanks x


Hi, i dont know how common it is, but ive been on letrozole for a year so far since chemo and my hair has come back really thick, no thin patches or anything.
Really hope it is the same for you, hugs, Julie


Hi @countrygirl1
I also started Letrozole before Radiotherapy and my hair continued to grow back. It was super curly, having been straight before! Once I had reasonable coverage, I kept getting it trimmed every 6 weeks so it was pretty short. After a year or so, the curls and frizz were gone, and although it’s not as thick as it was originally, it’s not too bad. I also used regular deep conditioning treatments, which I think helped.
I know a few other ladies on Letrozole, none of them have had issues with hair loss, hopefully you won’t either.


Thanks @jules_n and @NorthernJay I know hair isn’t the most important thing but I didn’t cold cap through chemo so lost it all and it’s such a lift to have it growing back now. x

I had chemo which finished 2 years ago this month, I started letrozole on 27th May 2022 . My hair came back once the chemo had finished and is now twice as thick as it ever was before my hair loss, so no it doesn’t affect everyone the same, hope this helps xx

I didn’t have chemo, but my hair did get thinner on letrozole

It took about a month after I stopped it to realise that there was no hairs on my hairbrush in the mornings.

So yes, I did notice it

Dear @countrygirl1 , I have now been on Letrozole for 5 months. My hair is growing back after chemo which finished 9 months ago. Having previously had greasy hair my hair is now extremely dry and thinning at the temples. Otherwise it has grown back mostly as before and is now about 1inch long. I only wash it once a week and treat it with aloe vera gel, and sometimes coconut oil. I also eat a very healthy diet and have vit d on prescription. Love Tulip X
P.s. I am 66 years old.

I’m on it 7 months and hair is growing well

Hi there I’ve been on letrozole since last october and all my hair, eyelashes and brows have grown back well. I did cold cap and so only lost about 30% of my hair so it was thin but its grown back really well.
The symptons I have had with letrozole are all around joint pain mainly hands and thumbs and fingers locking up but a small price to pay to try and keep the big C away.

good luck wish you well

I don’t know about most people but I have significant hair loss. I now have loss at the crown forward. Maybe it’s because I had surgery and radiation but no chemo? But then I also have significant joint pain and initially had only hot flashes and irritability. The effects from the medication has changed over time.

Hi Countrygirl

I have been on Letrozole for 8 months after chemo (loosing all hair) and radiotherapy. The worst side effect for me is joint pain especially Hands and feet but my hair is fine!

It’s grown back grey, thick and curly… I had a mane of long dark hair before so it’s different! But you know, it’s all fine, just pleased they found it all early enough to do something about it!

Good luck with everything.
M x

Hi, I am 71. Have been on letrozole …9 years by July and have a pretty good head of hair. I dont colour it , just wash and blow dry . I think it may be a little thinner at the front …but hey I will never know what my normal would have been .xx

Hi, I think Letrozole affects everyone differently. I was 68 when I had my mastectomy, followed by chemo ( no cold cap) and radiotherapy. I began Letrozole nearly 5 years ago just before my radiotheraphy. I lost all my thick, long hair during chemo but it gradually came back a silvery white colour. It is nowhere near as thick as it was but still ok. It grows fairly quickly and to keep it just about collar level my hairdresser cuts and styles it every 5 or 6 weeks. I used to have it coloured but now I am 73 I keep it silvery white, My eyebrows grew back nearly the same colour as they were before and my eyelashes have grown back black, just like before but that did seem to take longer. Letrozole mainly affects my knee joints badly but it is a small price to pay if this little tablet is hopefully keeping the cancer away. I wish you well. Take care.


Thank you so much for all your replies. I guess the answer to my question is “sometimes, and sometimes not”. My hair is growing back salt and pepper - slower on the crown. Used to have collar length hair that I had highlighted and regularly cut. Not sure what I’ll be doing with it now.

I know there are other worse sides effects of Letrozole. I’m 70 and already have osteoporosis. Had a five year course of alendronic acid weekly tablets that finished about 5 years ago and been taking Adcal D3 since then. I’ll be having a Dexa scan in the next few weeks as I haven’t had one for years. Will see how my bones are now. Worried as I know Letrozole affects bone density. Don’t want a broken hip!

Haven’t started taking the Letrozole yet. The packet is in the drawer. I would like to know what the percentage increase is in non-recurrence if I take it. I’ve been told I’ll be taking it for 8 years. Oncologist did say something about percentages but I didn’t take it in. He wasn’t very easy to talk to. Think I need to ask again. x

Hi @countrygirl1, most of us on Letrozole don’t complain about hair thinning but other treatments can cause it (such as Abemaciclib). We are usually moaning about heavy, aching legs and sore joints, my knees and hips hurt but a lot of women say it affects their hands too!!
Hope it goes well x

Hi @countrygirl1 firstly, I’ve had no appreciable hair loss on Letrozole but I didn’t have chemo and I am known for having very thick hair (too much to be honest) so may not notice but haven’t seen more hair on the comb. Nor have I had much in the way of joint pain. My SE are cognitive decline, low mood and insomnia. Also had some vaginal dryness which is now under control. As we know, it impacts all of us differently and some not at all.

With regard to percentage chances of recurrence, it is very difficult for anyone to give you an accurate forecast of that. At the beginning I asked my oncologist all of those questions (retired lawyer so need facts and causal links in every situation). She ended up quite honestly saying they just don’t know which is why most of them stick rigidly to the NICE guidelines. Having said that, you could ask your BC nurse to do the Predict test with you. Predict is really about survival rather than recurrence however it does give you different percentages of survival over 5, 10 and 15 years with and without endocrine treatment so in a way it is telling you something about the efficacy of your AI. A couple of caveats though - firstly, the Predict scores, NPI scores and all the other tools are based on the averages of tens of thousands of individual cases so there is no certainty that that precise percentage will apply to you and secondly, once you know what the percentage survival scores are, you can’t go back to not knowing if they are low. Many women base their decision on whether to take their AI on Predict, which is understandable but can be dangerous as it is not a hard and fast statistic, more a wet finger in the air. If you haven’t tried the pills yet, my advice would be to start. If you get SE, which many women don’t, then you can re-evaluate with your oncologist further down the line. Other than bone density loss, most SE go away eventually after you stop taking them anyway. I know it’s a hard decision and no-one can make you take them, it depends on how risk averse you are.

@Tigress Thank you for replying. There’s a lot to think about. Will probably await result of Dexa scan before deciding. If not too bad will try Letrozole for a while to see how I am. I’ve done Predict myself but maybe need to talk it through with BCN. I wonder how radiotherapy affects result. It’s difficult without that included. x

Yes, it’s an absolute bummer that it wasn’t developed with rads included and also, although I don’t know how relevant it is, the Allred scores because mine were high Er+ 8/8 Pr+ 6/8. But they don’t have the data from decades before, could only start collecting it recently so how much those of us considering treatment now would get out of it is questionable. When all is said and done, some of us will be lucky and get away without recurrence and some won’t and nobody knows which will be which. For full disclosure, I am on a Letrozole break at the moment after 18 months and, because of my age and Predict scores (favourable), I am considering giving it up because of the impact on my cognitive state.

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Both ER+ and PR+ were 8/8. HER2 negative. Yes, I know - I really should take the Letrozole :frowning:. Will see how I go with it. x


I’m on a mixture of drugs including letrazole and my hair has thinned but it’s still here ! I use a very gentle thickening shampoo and am careful styling it .

One other tip re letrazole is the brands give different side effects so if one brand isn’t working for you try a different one as you may be pleasantly surprised that you are ok by changing the brand rather than the letrazole all together. Definitely worth trying before stopping taking it .