Thyroid UK

I have stopped taking T3 due to heavy hair loss

I have stopped taking T3 due to heavy hair loss. I was on 150mg and doing great. I don't want to stop it as it was helping me a lot but my hair has started falling out in a big way so I don't feel I have a choice in case its the T3 causing it. As soon as I stopped some of my old symptoms have come back in particular brain fog and the lack of motivation to do anything. I also feel from time to time a bit down like I could have a good cry. I am having the worst week ever and that's obviously not helping things. My weight is now starting to creep on again even though my eating habits haven't changed. Any idea what to do about the hair loss?

15 Replies

It seems a little drastic to just stop if it was helping esp because both hypo and hyper can make hair fall out. Do you know if you've been on a little too much or too little?

Is your hair thinning or just falling? I ask because my hair never stopped falling out despite treatment (first levo, then a bit of t3), but it DID start growing in like billy-o so for a while it was thin but eventually it came back v thick like it used to be. I've been on t3 for a year now and it possibly has stopped falling like it was, fingers crossed.

Would be good if you could tweak it instead of chucking it if you see what I mean.


Hi, I'm on T3 only and a couple of years ago my hair started falling out. I recently had a vit D test done which showed I was insufficient. After a few weeks of supplementing with vit D 5000 a day my hair loss stopped. I'm still taking the same amount of T3. I suspect although I'm not certain that the vit D helped.


Good point. I think b deficiency can cause hair loss too - ?


Yes can't remember which one - if they know which one! please check irons ferritin folate & B12 anyway - I think it can be low Thiamine or Biotin too - perhaps adding T3 kicks up an underlying deficiency?

(Didn't connect lack of Sunshine (VitD) with hairloss... hmm.....) J :D


I have read that hair folicles are one of the few organs (if you can call it that) that need T4 to function, I have just spent 15 minutes looking for it but I cant find it. maybe you could mix it up a bit.



Quite a number of organs can convert T4 to T3. Hair follicles most definitely are among those!

It is, however, as clear as mud, how some people seem to function well on T3-only given how many parts of the body do special things with T4 - e.g. local conversion for the use of the cell itself, local conversion which is then released back into the bloodstream, transport across the blood-brain barrier and across cell walls, ... But they do!!!

J Clin Endocrinol Metab. 2008 Nov;93(11):4381-8. doi: 10.1210/jc.2008-0283. Epub 2008 Aug 26.

Thyroid hormones directly alter human hair follicle functions: anagen prolongation and stimulation of both hair matrix keratinocyte proliferation and hair pigmentation.

van Beek N, Bodó E, Kromminga A, Gáspár E, Meyer K, Zmijewski MA, Slominski A, Wenzel BE, Paus R.



Both insufficient and excess levels of thyroid hormones (T3 and T4) can result in altered hair/skin structure and function (e.g. effluvium). However, it is still unclear whether T3 and T4 exert any direct effects on human hair follicles (HFs), and if so, how exactly human HFs respond to T3/T4 stimulation.


Our objective was to asses the impact of T3/T4 on human HF in vitro.


Human anagen HFs were isolated from skin obtained from females undergoing facelift surgery. HFs from euthyroid females between 40 and 69 yr (average, 56 yr) were cultured and treated with T3/T4.


Studying microdissected, organ-cultured normal human scalp HFs, we show here that T4 up-regulates the proliferation of hair matrix keratinocytes, whereas their apoptosis is down-regulated by T3 and T4. T4 also prolongs the duration of the hair growth phase (anagen) in vitro, possibly due to the down-regulation of TGF-beta2, the key anagen-inhibitory growth factor. Because we show here that human HFs transcribe deiodinase genes (D2 and D3), they may be capable of converting T4 to T3. Intrafollicular immunoreactivity for the recognized thyroid hormone-responsive keratins cytokeratin (CK) 6 and CK14 is significantly modulated by T3 and T4 (CK6 is enhanced, CK14 down-regulated). Both T3 and T4 also significantly stimulate intrafollicular melanin synthesis.


Thus, we present the first evidence that human HFs are direct targets of thyroid hormones and demonstrate that T3 and/or T4 modulate multiple hair biology parameters, ranging from HF cycling to pigmentation.





You should check with your GP about your hair loss. There could be several reasons.

Obviously, one is being hypo. Second it can be due to an autoimmune condition. My personal belief is that the dose of meds can be too low or the levo isn't working as it should.


I had hair loss on T3 Levo combo. Endo suspected T3 but I thought it was due to hypo. I increased dose and hair loss stopped. It's difficult to know what's causing hair loss, and it's scary. Has the hair loss stopped now you've stopped T3? Follow your instinct would be my advice.

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Hi guys,

Thanks for your replies. I stopped taking T3 completely this past week as I was very scared at the extent of my hair loss. It comes out in clumps and the other day I just touched my head with my hair brush and clumps clung to my brush with ease. It is very very scarey. I had enough hair for four people as extremely thick hair is a family trait of ours but now I can see my scalp and the odd bald patch.

After I posted my message on here tonight I decided to take 25mcg of T3 and perked up within half an hour of taking it. I feel much brighter again. I have now started catching up with some of my work with a new sense of motivation. I work from home and my work is all about deadlines but this past week I have just been looking at it all and have not cared whether I met deadlines or not. I have also made lots of mistakes due to the brain fog.

When I stopped T3 completely for a week or so my hair loss slowed down but it was still there..

I now realise I can't live without T3 at all.

I have tried up to 200 mcg Levo when I was seeing Dr S last year but that made my symptoms much much worse and then tried NDT which gave me violent stomach pains. However T3 worked a treat.

I probably could do with some T4 as well but I am self medicating due to lack of interest from my GP. I still have a lot of supplies of Levo left so I might add in say 25mcg of T4 and mix it up a bit and see if that stops my hair loss.

I am already taking 10,000 IU a day of D3 as my vit D levels are extremely low at 23nmol/L. My serum ferritin when tested last year was 224ng/ml in a range of 34- 528 and my serum vit B12 was 628 ng/l in a range of 220 - 914.

It feels good to know you all know what I am going through.


Its been a are you feeling???


I support the comments on VitD and B12 - I have increased both greatly since being on this forum and YES - my hair has improved. Have been T3 only for over a year....

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Marz. What were ur tsh levels. I have t3. Havent taken it yet. 23 months hair loss. It has stopped shedding alot this past 8 weeks since stomach treatment for hpylor. But all hairs are finer and weaker than they were everywhere on body diffuse hairloss and what their is, us weak. Tsh t3 t4 within rane not optimal. Peroxidase 91. Going to get my thyroid tested again. To check if been a change for the worse this past 3 months since last tested.


Would have to look it up. This thread is 4 years old. Busy morning - will try and reply later 😊


Thabks marz no rush at all


TSH well below range and always highlighted - I test only once a year. I was T3 only for quite a few years but introduced some T4 last April time. As I thought I had improved my conversion from T4 to T3 with supps - I decided to go for it. FT3 now much improved. Due annual tests soon :-)

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