Thyroid UK

Can TSH be too low with reasonable FT3/ FT4 ?

Hurray, got the FT3/FT4 done NHS.

NHS 13/7/16 TSH 0.03 (0.27 -4.20) on 1 1/4grains Armour

FT4 18.4 (12.00 - 22.00)

FT3 5.8 (3.10 - 6.80)

Genova 13/4/16 TSH 0.13 (0.40 -4.00) on 3/4 grains Armour

FT4 18.4 (11.5 - 22.7)

FT3 5.3 (2.8 - 6.5)

There doesnt seem to be much difference between the two results in 10 or so weeks. The TSH has now been flagged up as too low , and i wondered how low can i go please ?

I have Hashi's (antibodies going down since grains and soya were ousted) still freezing core and extremities last week, gasping for air with todays weather, but strangely cold core.

Im still struggling to get my iron up ,last Ferritin was 33 in April and i suspect has dropped a bit more since soya free , i take Floradix and have inflammatory gut problems with that tiny dose as and when.

Should i increase my Armour to 1 1/2 grains even if my TSH is 0.03 or should i wait until i can get my iron up ? My temps are still 36.5 am/pm, pulse 78-80 if the gut pain keeps me awake i notice the temps can drop to 35.5am/pm , pulse 60, i presume thats because my cortisol shoots up ?

I felt dreadful all last week , no energy, itchy, weak, aching muscles,dizzy, sweating and freezing, but a noticeable improvement after iron rich food, when i can eat.

As always, any advice gratefully appreciated please. G.

17 Replies

It doesn't matter if TSH low or suppressed. It's free T4 and free T3 results and your symptoms that matter and those results look OK to me - in upper end of reference range.

1 like

thank you Hoxo for such a swift reply, although ive gone from housebound to moving around and getting out in 18mths, still craving the old life....... and still not fit to work..........but i gather the longer you were 'in it' so to speak the longer it takes to get out, so bit more patients methinks.

Every best wish G.


The hypothalamic pituitary thyroid axis can be down-regulated if hormone levels are high for a sustained period. It looks like this is happening here. There can be a number of consequences. The TSH no longer reflects the hormone status. The low TSH will presumably lead to reduced T4 to T3 conversion as TSH stimulates type 2 deiodinase.

This down-regulation is sometimes reversible, so it helps to reduce your medication if you can. Often we are caught between a rock and a hard place. We don't want to suppress the TSH because of the above effects but often we are ill unless the TSH is suppressed (for some reason we need above normal hormone levels). My general advice would be to try and avoid suppressing the TSH but if you have to then do so as you need a life. (When I say try I mean try for a couple of months or so).

It is difficult to interpret blood tests when taking T3 medication, I would leave four to eight hours after taking the hormone before having the blood taken - this should give the most realistic numbers assuming the hormone is taken twice daily.

1 like

Hi Jimh111, thank you for your reply, i think your post was for me, im not taking T3 on its own if i understood you correctly?

My start with thyroid meds was just 18mths ago, on the 1/4grain for 9mths (never had Levo) with Armour, my increase has been over several months not fortnightly as most do, due to complex gut and all the other here mentioned mins/vits being way too low.

Im not sure im informed enough to understand all you said, but having gone from a 16hr day active life, 2 jobs for years ,down to housebound up until 18mths ago and Armour changed that. I have to say that taking the meds doesnt actually feel very 'normal' and its clear that the T3 kicking in kickstarts my day, but all is not right and im still not able to work.

If your post was meant for me, im not sure how to exist with less than 1 1/4grains.

Every best wish G.


Hi Gillybean, Yes I did mean the post for you. As you have increased your Armour very slowly and suffer major effects on your life I wouldn't worry about the TSH. It is desirable to avoid suppressing the TSH if you can but it is a question of balance. Sometimes patients go onto high doses quite quickly without giving the medication the time it needs (several months).

I've just noticed you have sufferred whiplash. It would be really interesting to see your first thyroid blood test results. Patients with whiplash can suffer 'central hypothyroidism' which means the pituitary does not produce sufficient TSH. It can also affect other pituitary hormones. So this is a possibility although looking at your fT3, fT4 in this post and knowing you are on Armour I would expect your TSH to be in the range it is.

If I may sum up although your TSH is suppressed I would continue with the Armour if it is making you better and titrate it on your symptoms, find the lowest dose that makes you well. It's a bit like taking anti-biotics, it's not a good thing to do but if it makes you better then you should take them. The same with suppressing a TSH, try not to but do so if it is the only way to get better.


Just a punt, but could it be that you're not converting very well? That could be why you have so many of those symptoms we associate w hypothyroidism (and the ones that often go away first when you start taking meds, like feeling cold). I wonder if you'd feel well on t3 alone. Have you read Paul Robinson's book Recovering with T3?

I say this because t4 should fall if you're taking t3 (Armour has both), and these results show quite a lot of t4. If you were on levo alone I'd say this is a brilliant result, ideal numbers.

I hope someone else will weigh in and confirm or deny as I'm not an expert and am only informed my my own experience.

1 like

.Hi Puncturedbicycle, thank you for your reply, apparently i convert ok ,but of course the burning question is then how am i using it....dunno.

I understand that long periods of physical pain (3years dble whiplash) would have raised cortisol and that in turn would inhibit T3 uptake, but that pain has gone to be replaced with chronic gut pain/inflammation, so there will still be the adrenal aspect etc.

I didnt know that about F T4, re Armour, i just thought we had to get the F T4 as high as possible.

Every best wish and thanks again G.


How was it determined that you are converting?

If you were on levo you'd want to see t4 high in the range, but once you introduce t3 your t4 will fall. It's odd to me that yours hasn't.


Hi Puncturedbicycle,

It was determined before i started meds, that there was some FT4, some FT3 all much lower than now so it was considered that i was converting, but of course not possible to know what i was doing with it at cell level. This was all when i was housebound , with soaring antibodies, air hunger, unable to digest anything on liquids only with chronic gut and malabsobtion problems rising TSH 4.8 if i recall, and the Endo's were divided, one wanted to treat 25mg Levo, one wanted to wait till thyroid failed, another wanted to treat when TSH reached 10.

As i was left on liquid supplements meals only, getting weaker and weaker, written off by the NHS and unable to exist i opted to try something on my own and chose NDT and because i was reacting to so many things i thought this might be the safest choice.

Youve got me curious now, if T4 should be dropping, i thought the aim was to get FT4 as high as possible. ?

There was a string of things going on when this all kicked off as a slow burn 10years ago, from dble whiplash causing chronic pain 24hrs for 3years (neck trauma) no sleep = raised cortisol= poor T3 uptake for some time i suspect= poor gut= malabsorbtion=coeliac undiagnosed for some time=osteopena, and massive mineral loss from a 50day menstrual bleed. None of these help the situation.

So am i barking up the wrong tree here methinks, were the Endos right saying no meds required? Or are you meaning Levo might suit better?

The only medic that suggested try 25mg Levo and see if symptoms subside also expressed caution because i cant cool down (side effects) as well as cant heat up. Plus for me a novice at the time noticed Levo wasnt Gluten Free.

Thank you for your reply, G.


No no, wondering if t3 (only) would suit better. It's just an idea. Your t4 would be ideal if you were on levo, but on a combination like Armour it seems odd to me. I wonder if the t4 in your Armour doesn't agree with you.

Heat intolerance is what I experienced when I first went on levo. I felt a lot better in terms of no longer being freezing all the time, but suddenly I'd get in a panic if, say, I had my coat on and was waiting in the hall for someone, I had to go outside or I'd want to rip my clothes off. So it can be a hypo symptom too. I don't have it anymore.

So it seems like some element of Armour is helping, but it isn't solving the problem. And your levels are as good as they're going to get (from my layperson's perspective) in that your tsh and t3 are pretty good, though your t3 could be a little higher.

Hoping someone will see this who is more in tune with the needs of t3-only people. I'm only making a semi-educated guess. :-)

What an awful time you've had. I do hope you get to the bottom of it. x


Oh my, totally get the standing in the hall clothed up waiting to go,,,,,and in just seconds 'you feel the benefit of your coat' as our Mum's used to say, and you overheat so fast ,even on a cold day,and you just cant get things off quick enough because even that action of moving fast to do something raises your core heat........madness, but you say that stopped for you. When ? Years into Levo? or an age thing ? Youve just raised my hopes, thank you, even if it doesnt come to me its useful positive knowledge that things do change for people.

I must admit, sometimes i look as though i got dressed in the dark !! the layering of clothes that come on and off throughout a day!!

Yes the T3 is a possibility either to reduce NDT and add in, or T3 alone. Cant help thinking im doing something wrong,or missing something simple, even if it was to get to sleep earlier to support adrenals.......

Thank you so much for your words, best wishes Gx

1 like

No worries. :-)

I think the heat intolerance went pretty quickly, or maybe once I started a bit of t3. I remember it as an early-stage thing.

Levo helped me with the feeling cold all the time and I think my hair stopped falling out so badly but didn't seem to grow in.

T3 helped alleviate the bloating, tiredness, breathlessness, weakness and constipation, and my hair (head and eyebrows) came back like billy-o. I still have a lot of tiny short hairs on the periphery and that never seems to change, so maybe it's still falling out but growing in at the same rate? It looks a little crazy because those baby hairs are always waving about and I can't keep them tidy, but I'm so grateful for thick hair.

B12 helped my sore feet, numb toes and tinnitus (but only injections, not oral supplements, which didn't do much of anything, even on high doses).

D helped my sore, weak hands.That seems like my most prominent symptom of low d.


The baby hairs sound rather youthful and nice.....but if they drive you mad have you tried Argan oil on them, it calms things down , goes on oily then within 5mins dries silky and non oily. I speak as someone who has gone from sleek plentiful locks to what i can only describe as Yorkshire Terrier's eyebrows sticking up all over the place!

I can empathise with all of those symptoms you had before the T3 kicked in.

I remember waddling into the GP (pre meds) complaining that i had been 8stone for 30years and in the last 2mths had not been able to eat/digest properly and ballooned to 10stone in that short time, to be snapped at "well why have you done that"............. not very helpful.

Fortunately a new GP took one look and said 'chronic malabsorbtion, coeliac disease and Vit D defic' she was spot on as test concluded.

Many thanks again, you have given me a bit more hope after a rough week. I soon bounce back, still looking for my sweet spot.

Enjoy the blue bright skies G.


Ha, baby hairs are more 'crazy old lady' than youthful but thank you for your argan oil tip. I will give it a go.

I'm glad to be helpful. I remember feeling so hopeless myself and worrying it would never get better. You can't necessarily plan what will improve and what won't, but as long as things get better I'll take it.

Yes, all the best to you and hope you too are enjoying the weather.


Love the blue skies and the cheery faces, but gone from twiglet legs and blue toes ,central heating on last week to puffed up adder the last 2 days with feet and fingers so full of water they wont bend............clearly not found my sweet spot yet.

Yep , not throwing in the towel yet, im a great believer 'there was a way into all this, there must be a way out' but always lovely to hear that you have found a balance.

All the very best G x


What about vitamin D levels? B12? And magnesiu m too - no point testing magnesium, mist are low. Can supplement, unless have kidney issues, most of us are low in magnesium apparently


Hi SlowDragon, Thank you for your reply D, B12 all good and high, Mg and Ca supplemented too as i have osteopena, which Mg and Ca blood test did not show, just read as completely normal.

I noticed i had lost 1 1/2" in two years, asked for a DEXA scan, and after much deliberating was finally given one and showed osteopena from chronic .malabsorption. These things dont happen overnight so i must have been poorly absorbing for 5/6years without knowing.

Every best wish G.


You may also like...