Feel terrible, increase dose?: Hi all, I'm... - Thyroid UK

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Feel terrible, increase dose?

Pearlteapot profile image

Hi all, I'm feeling terrible, horrible brain fog, feel like I've got brain damage, can't work, keep crying.

I was diagnosed 19 March with TSH 71 and started on 50mg mercury pharma. On 19 April my TSH was 15 (from an afternoon test) and on 28 April doctor increased my dose to 75mg. The brand name of the other 25mg is in my bio I think. So it's only been 2 weeks since my last dose increase.

I don't know my current TSH although I recently sent off a private blood test because I wanted to test my T3, so I will probably get that result over the next few days. My next NHS blood test is not due till 23 May.

I just spoke to the duty GP and asked if I could increase my dose to 100mg. He said two weeks is really too soon but eventually agreed that I could. My resting heart rate is 49 and my blood pressure is 'optimal' (wording from the app!), staying consistently around 110/70.

I'm not sure I do fully understand the risks of increasing my dose so soon. With such low resting heart rate and good blood pressure the heart risks seem minimal. What am I missing please? What are the arguments against increasing dose after only two weeks since the last increase?

Meantime I feel like I'm getting brain damage from lack of thryoid ib my brain. Is that even possible?

25 Replies
SlowDragon profile image

See how you get on taking 100mcg

Which brand of levothyroxine is your 50mcg tablets

I see from previous post 25mcg is Wockhardt

Essential to test B12, folate and ferritin if not tested yet….or was this included in your private test

No point getting retested on NHS until 6-8 weeks on 100mcg

Book early morning appointment, ideally before 9am and last dose levothyroxine 24 hours before test

Approx how much do you weigh in kilo

I’ve just updated my bio with my ferritin and folate tests from March. Ferritin saturation is a bit high but I don’t know what that means. I’m 77kg approx

The 50 Levo is mercury pharma.

SlowDragon profile image
SlowDragonAdministrator in reply to Pearlteapot

No mention of folate or ferritin on profile….?

guidelines on dose levothyroxine by weight….at 1.6mcg per kilo as approx guide

That’s about 123mcg per day at 77kg …..so going up to 100mcg should be fine

Even if we frequently don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until eventually on, or near full replacement dose

NICE guidelines on full replacement dose



Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Also here



Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months. RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

BMJ also clear on dose required




Ah, it didn't save to my profile. Sorted it out now. My folate is 5.1 against range of 2.9 - 50. My B12 is 762 against range of 160-925. My ferritin saturation is 47.4% against range 20-40.Quite low folate. What does that do? I'll search.

I think they wanted to titrate me because I am over 60 (since a couple of weeks ago) but its useful to see the BMA guidelines suggest going to full dose if under 65. I'll take 100 tomorrow.

Should I be adjusting my folate? Could it explain me feeling so terrible? I am already supplementing D3. The intense course from the GP has finished but I am now taking a omega/D3 oil.

SlowDragon profile image
SlowDragonAdministrator in reply to Pearlteapot

Suggest you initially increase to 100mcg or 75mcg on alternate days…..wait 4-6 weeks before increasing to 100mcg daily

What vitamin supplements are you currently taking

Are you supplementing a B12 on its own?

For low folate

Rather than just taking B12 supplementing a good quality daily vitamin B complex, one with folate in (not folic acid) may be beneficial.

This can help keep all B vitamins in balance and will help maintain B12 levels too

Difference between folate and folic acid


Many Hashimoto’s patients have MTHFR gene variation and can have trouble processing folic acid.


B vitamins best taken after breakfast

Thorne Basic B or Jarrow B Right are recommended options that contains folate, but both are large capsules. (You can tip powder out if can’t swallow capsule)

IMPORTANT......If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before ALL BLOOD TESTS , as biotin can falsely affect test results



Hi Pearl teapot. It takes a while before you feel better. I started levo last May starting at TSH161. I gradually built up to 75/100 but it took a lot of months before I felt a lot better. I had a check up in November and it had taken six months to get results in range and for me to feel better but even now a year later I still feel I'm recovering. Be patient and hopefully things will improve.

Lulu2607 But why did you build up so gradually instead of moving faster to full dose? The links that SlowDragon has posted suggest going straight to 1.6mg per kG of patient weight if under 60 and no heart problems. The BMA says the same but for age range under 65.

So what are the advantages of tolerating feeling so terrible for longer in order to go slow? There must be some, this is what I am wondering.

Lulu2607 profile image
Lulu2607 in reply to Pearlteapot

Hi Pearlteapot I had to wait for the blood test results at 6-8 weeks each time before increasing and after 75, another blood test, then tried 100 which was another blood test but felt that was too much so trying 75/100. After each blood test there's a delay before you can discuss the results with a Dr. and change dose. I also have other health concerns to consider. Also, you don't get the full effect after a couple of weeks although you may feel some difference. Everyone is different in their response to levo but it always takes a while to get it right. I'm not sure I'm right yet but I'm giving it a month at least on my new dose before I decide.

basically it's just because if you go too fast , and don't give each dose a reasonable length of time to settle in, then it is really easy to miss the right dose for where you would feel best .

and if you take more than you need , you will feel just as naff as if you take less than you need.. it's very hard to tell the difference between what 'a bit too little' and 'a bit too much' feels like ... and you can't really tell anything at all after only 2 weeks on a dose , due to how long it takes your body to re balance it's own hormone imput & conversion to T3 ,whenever the dose is changed.

Don't worry .. you (probably!) won't drop dead or have a heart attack just by effectively going straight from 50mcg to 100mcg... i did that and was perfectly fine , (mind you i was only 37 and my TSH was only 6.8) .... but DO keep a very open mind to the possibility that your right dose might have been eg 87.5mcg (or 112.5mcg ) regardless of what the 'dose by weight' guestimate says .... it 's really not a very accurate guide at all.

With hindsight ,i think i made an impatient mistake when i went up in one jump from 100 to 150mcg .. i suspect i would have done well to try 125 and 137.5mcg for several months first.... as it was , on 150mcg i had 'energy crash' issues that looked like M/E, and a lot of recurrent muscular problems, but when the GP had initially asked me to try reducing to 125mcg, i only tried it for about 2/3 weeks before saying 'no , this feels worse' and going back to 150mcg ..... for 15 years .

I will never know how different those 15 yrs might have been of i'd been on a very slightly lower dose like 125 or 137.5 ..... but if i had my time again, i'd give myself longer and make sure i had the opportunity to find out .

After menopause i became clearly overmedicated on 150mcg , and this led to a few dose reductions, 125 /112.5 /then 100 , and back up a bit to 112.5mcg .

Observing the subtle changes on these different doses , and how long they took to settle in, and allow improvements in symptoms, has taught me a lot about adjusting thyroid hormone dose that i didn't understand when i was first increasing my dose.

The tale of The Tortoise and the Hare was never more appropriate ..... you'll probably be fine on 100mcg , but give it a full couple of months at least, before you consider making any further changes , and then do them in much smaller jumps of no more than 25mcg (and if TSH is getting near 1 and/or fT4 is getting near top, then 12.5mcg is more sensible ) , and always wait 6 weeks at the very minimum to see how it feels , but more realistically you want to give any dose change more like 8 -12 weeks to really see how it feels in future .

SlowDragon profile image
SlowDragonAdministrator in reply to tattybogle

Great advice …..so easy to miss the sweet spot by rushing up

That’s strange. I had replied to tattybogle but it seems I didn’t manage to upload it. Very helpful advice thank you. I know I’m being impatient but I take some comfort from the nhs guidance saying to go to 1.6mg per kg of patient weight if under 60. I think SlowDragon suggestion of alternating 75 and 100 sounds good.

May I ask what over medicating feels like? I was quite surprised to see you describe it as an energy crash as I would have expected the opposite, more like feeling hyper, palpitations, lack of sleep. It’s obviously more complex than that.

Have decided against folate supplementation by the way. I’ve been reading up on the high tranferritin saturation. My mother has haemachromotosis and I thought I’d been genotyped but I e just checked old correspondence and I haven’t been. So that will be my next step.

Lulu2607 profile image
Lulu2607 in reply to Pearlteapot

Hi. When the blood results suggested I was overmedicated I didn't feel too well. I had night sweats and sometimes during the day whereas before I hardly perspired at all, and I had very vivid dreams. Like you I thought I'd be full of energy but not really and my moods were all over the place which didn't help, and I started to put weight on (?) although I had begun to feel hungrier, particularly for carbs mid afternoon. I've reduced my dose slightly and those symptoms have also reduced somewhat. Not so many vivid dreams and my weight is a bit more stable. I find it easier to control my appetite too. I feel getting my dose right will be tricky. I didn't like alternating 75/100 so now I'm trying 87.5 but not sure if I'll need the occasional 100. It's a long old slog for all of us.

SlowDragon profile image
SlowDragonAdministrator in reply to Pearlteapot

So you haven’t had testing for hemochromatosis?


No. I thought I had been genotyped decades ago but it seems I misremembered. What a terrible mistake. I had my thyroid scan this week. I don’t have official results yet but the lady who did it said very clear thyroiditis. I had the impression my thyroid is destroyed. My appointment with GP is not for another two weeks. I might write and ask for the appropriate tests though. Liver function is within normal range so that’s something good!

So just to be clear . i can't be sure that the energy crash thing was slight overmedication or not .. it's just a growing suspicion i now have that it might have been related.

However , after menopause, when i definitely had become overmedicated.. it was not easy for me (or several GP's) to initially recognise it was overmedication from my symptoms, (or bloods ).

While it's probably true that being very, very overmedicated will almost certainly present like 'classic' hyperthyroidism to some degree .... when it's a case of being 'just a bit overmedicated' it can be much harder to see the wood for the trees .

It's going to be very individual , like everything 'thyroid'.. but for me .... this happened:

I had been having really nasty '?kidney area' pains coming and going for months , my bladder was tense and always uncomfortable ,and i was constantly feeling like i needed a wee, i once counted 14 trips to the loo before i left the house in the morning, and was mildly incontinent occasionally ... easiest way i can describe is ... a bit like having chronic cystitis ,but without the burning .

I had lost a bit of weight , but i wasn't remotely hungry, so hadn't been eating much at all , and so i wasn't surprised about the weight loss.

I was extremely jumpy , if a car horn went off, or there was a sudden noise ... i would literally 'jump'.

I was getting dreadfully clumsy, the tea spoon was always missing the cup and spilling sugar on the counter.

My eyesight seemed to be getting worse rapidly.

I felt so stiff and 'frozen' in the mornings i needed to lie in warm bath for an hour before i could face going to work. Then when i got there i would be sweating at the slightest exertion.

I was about to get the sack for being in a worse state that the people i was supposed to be looking after.. so i left voluntarily

I was much more exhausted than usual.

I felt dreadful ... like i was dying to be honest... and interestingly , my energy crash 'thing' was much worse than usual.

..... but my heart rate wasn't fast ..... my blood pressure was fine .... my sleep was no worse than usual..... my thyroid bloods (when somebody eventually thought to do them) were not much different to any others i'd had for the last 10 years , except that my TSH instead of being it's 'usual ' 0.05 ish was a smidge lower at 0.018 ......( my fT4 was very slightly over range , but it had been more over range than that several times before and i was ok with it then ... and mine always wanders around a bit for no apparent reason )

Anyway......one GP found calcium oxalate crystals in my urine, but no infection ...... they ordered an ultrasound of kidneys to look for kidney stones, but found none ...... another GP referred me for endoscopy /colonoscopy / CT scan etc to make sure i didn't have cancer somewhere .... i didn't.

Anyway .... while all this was going on , i'd gone back to the GP to check up on a 2 week referral that hadn't appeared , and got this elderly female GP .

She actually looked at me properly ,and then said ... "hold your arms out in front of you...." there was a very fine, barely perceptible tremor in my fingers (classic hyperthyroid / overmedication sign ).... " has anyone tested your thyroid bloods yet ?, they should have done that first ... i think you're just overmedicated "

Sure enough , a reduction from 150mcg to 125mcg solved most of the above problems within a few weeks, and the rest gradually disappeared over the next couple of months.

Shame i didn't see her first .....it would have saved the NHS a fortune ,and me several months of pain and worry .

Don't expect 'hyper' to feel "too fast, over energetic and insomniac "... it doesn't .... it just feels like a slightly different kind of slow death to being hypo.


tattybogle thanks, very descriptive. Oh my god. It does feel like slow death. The GP and Internet give the impression that you just take a pill and it’s all fine. It’s such a common disease doncha know! I suppose those that are well medicated and not suffering aren’t hanging around this forum, but still. Maybe I’ll press on for longer at 75mg, however rubbish I feel. At least till my new test results come through.

I just want to get back to life!! Waaa!!!

it's very common, sure .... but it's not simple ... thyroid hormone affects the correct function of more or less every cell in your body , and the body's regulating/ feed back / feed forward control system for our thyroid hormone production /balance/ conversion to T3 , is one of the most fiendishly complex in the body , and is only partially understood even today , and the autoimmune component of the disease is still in the 'too complicated' box .

GP's do us (and themselves) no favours with this "one little white pill a day, and you'll be fine in a few weeks" attitude .

I do know some people who really are very well on levo, without much bother ....and you're right, you won't find them hanging out on here.

But i have my doubt's that there are really so few people with 'difficulties' as the GP's would have us believe .....

When i first came here about 2 yrs ago there were about 106 ,000 members on this forum ... today there are 124,688

SlowDragon profile image
SlowDragonAdministrator in reply to tattybogle

Approx 24 years ago (long before internet and patient forums)

After about 5 years being on levothyroxine, by then very unwell and I was very slowly being sent around numerous NHS departments….

eventually on one of my many trips to NHS endocrine centre of excellence……

lovely lady thyroid specialist endocrinologist…..said ….”we see hundreds of patients like you for whom levothyroxine alone just doesn’t work”

…..it was such a relief to hear that I wasn’t some ridiculously rare case!

Oh wellThat’s me shown. Last night (3 days after dose increase 75 to 100mg) my heart rate spiked from its usual 48-60 range to 133 while I was sitting down after dinner reading Twitter. Ankle oedema. I live alone and was frightened so went to A&E.

So I’d better reduce dose back to 75 even though I felt terrible on it. Maybe in time I’ll try SlowDragon suggestion of 75/100 but for now I need to stay safe. I’m seeing an endocrinologist on Monday anyway which has been lined up for ages.

SlowDragon profile image
SlowDragonAdministrator in reply to Pearlteapot

Stick on 75mcg for at least 8-10 weeks before retesting

You increased too quickly

Sadly we have to wait for whole body to adjust to each dose change

Meanwhile working on improving low folate

Perhaps consider testing Dio2 gene

Test not yet available on NHS



Welcome to the wonderful world of "I need to replacing my missing thyroid hormones "... the disease that comes with a Do-it-Yourself Endocrinology 'A' level ..... and a Diploma in 'Patience'...whether you wanted to learn either of them ,or not.....

Really spending too much time on this forum and reading endocrinology but seems unavoidable! Hospital doctor last night told me my thyroid was responding well because TSH of 15 ( which is actually an increase and the sample was taken in the evening after dinner so actual situation could be worse). I didn’t remonstrate as I was just happy to be in a hospital instead of home alone with a spiking heart. ❤️

wonder how on earth he came to that conclusion ... Hopefully he meant "15 shows you're responding well to levo, because it's much lower than the 70 it was at diagnosis"

you do hear some very illogical comments from medics reported on here ... in my more charitable moments, i give them the benefit of the doubt and hope that they do actually understand what they are talking about better than their comment made it sound , but they just didn't have time to explain their reasoning to a patient who they assume has little understanding of the in's and out's anyway ...... but you do wonder about some of them .. if he actually meant "15 means you are well" that's scary . but presumably they can see previous result of 70 on computer so hopefully he meant 'your improving' not 'you're well'

as for spending a lot of time on here .... it's a smart move ..... " if you want something doing properly .. do it yourself ".

give yourself longer to acclimatise to 75mcg ... have 6 weeks back on 75mcg . (starting from now ....unfortunately .... as in 'tortoise and hare' ..... you now have to wait a week or so longer because your body needs time to settle down again after you increased a bit too much too soon) .

:) we've all been there .... that's why we all sound so patient now .. most of us have learned it the hard way too .

Thanks SlowDragon. If I understand you right you’re suggesting the Dio2 test because my symptoms might suggest being over medicated (heart, sudden stool motility) but also under medicated (intense brain fog, ankle swelling ). I’ve sent off for it. Worth checking.

I have started a folate supplement. Can’t remember quantity will check when out of bed! Got back from hospital 3am 😌

SlowDragon profile image
SlowDragonAdministrator in reply to Pearlteapot

Dio2 is common gene variation

Thyroid patients who test positive often need addition of T3 prescribed alongside levothyroxine, once levothyroxine is at correct levels

Important to fine tune levothyroxine dose first, get all four vitamins tested and optimal and frequently gluten free and/or dairy free ….

Dio2 gene doesn’t mean we can’t convert Ft4 to Ft3….but we may need some T3 prescribed alongside levothyroxine……brain and heart need constant levels of T3

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