Why does Levothyroxine make symptoms worse?


I haven't posted on here since I was newly diagnosed and seem to have come full circle to the place I was in 3 years ago.

I have hypothyroidism which started after the birth of my second child. I was prescribed T4 which had adverse side effects. I stuck with it, taking 75mcg, until my daughter weaned from breastfeeding about 18 months ago.

I felt a real shift at that time and started to reduce my T4. I felt better and better on lower doses of T4 but my lab results always came back as significantly hypothyroid. I tried T3 but felt really anxious and jittery on T4 / T3 combined. Actually, the anxiety was the worst symptom to deal with on T4 alone too. I felt like my stress levels were constantly so high... I am not usually a stressy person.

I stopped eating gluten last October and after 2 months of feeling awful my symptoms all disappeared in early January. At this point I was down to 25 mcg T4 and felt better than ever. I started to feel jittery and was having a hard time sleeping and decided to try without T4 at all. During this time I felt calmer, my basal temperature remained at a steady 36.8C, I didn't have any symptoms as I carefully monitored myself for the six weeks after stopping medication.

Then I caught a virus, a throat infection that stuck around and stuck around. I really could not shift it and this set off alarm bells. I also was feeling dizzy at times and lost a lot of weight very quickly. I just felt wrong. So I went to get my levels checked and my thyroid is miles out of range again (similar to when I was first diagnosed) TSH >100, T4 1.7

I have started on T4 again but this time on the liquid solution. I no longer have the anxiety issues but I have so many other symptoms/side effects - my hair is falling out, I am so cold, my temperature has dropped to 36.1, I have headaches, I crash out with tiredness in the middle of the day, my mood is low and I wake up with the worst aches and pains.

I have been trying to slowly increase my dose of T4 as I know that being undermedicated can be a problem but each time I increase everything just gets more severe.

I really feel like I'm going a bit mad. I feel well when I don't take medication but I do need the thyroid hormone, but when I take it I feel so unwell I can't function properly. The endocrinologist I saw last suggested I could have something with my adrenals but then said just to keep trying to increase T4 very slowly.

Does anyone have a similar experience to this or know why Levothyroxine might give so many side effects? I finally have a decent GP who said I could do better on NDT but she's not allowed to prescribe it so I've got to try to get back to the endocrinologist and persuade them to let me try it.

Sorry, this turned into such a long-winded rant. I just want to know more about replacement hormones really and what options I could try to balance my health again.


35 Replies

  • Kat,

    I had awful side effects on T4 that were resolved when I added in T3.

    Your GP can prescribe NDT on a named patient basis. There are templates and more information on thyroiduk.org If your GP declines to prescribe perhaps she would oversee you while you self medicate with NDT bought online. PM me if you want a source.

  • Thank you for your reply! I have tried T3 in the past but it just seemed to accelerate the side effects of T4. I will go back to my GP and ask again. It might be at this particular practice that they wont let her prescribe. She said she had campaigned for months for her hypo patients in the past with no success.

  • Kat,

    If she won't prescribe T3 or NDT ask her if she will monitor you if you buy it online. If she won't, you will get advice and support here which will always advise starting both low and slow to ensure tolerance before increasing doses.

  • Hi Clutter just saw my Endo this week and mentioned the named patient basis, but to no avail. She said that they will only prescribe the medications that they feel confident with and are familiar withe ie Levo and T3, which I have. Wow it took me nigh on 20 years to get them to trial me on T3. I am taking Cynomel at the moment as no choice as my prescription is not ready. Just for two days I feel the kick from it, it is a lot stronger than the NHS T3. However I will have to used NHS or they will take me off it and I dont want that. All trial and error.

  • If you're comparing 25mcg Cynomel with 20mcg Liothyronine that might explain the difference. Have you tried increasing your Liothyronine to 30mcg to see how it compares with 25mcg Cynomel or even 50/50 Cynomel to Liothyronine and see how you feel?

    Bottom line is to take whatever makes you feel well. If you can afford to buy Cynomel you can collect your Liothyronine scrips but don't get them filled.

  • Hi Clutter yes I am just taking Cynomel until I get my prescription. I will be upping to 30mcgs when I get it as Endo has advised and reduced T4 to 50mcgs. She has given me a repeat prescription now for the next 6 months up to my next appointment, so I don't want to miss out on that. She has trialled me for 3 months so I think that I have earnt it. Just wish everyone to get it, it only took me nearly 20 years. Do you mean take half NHS T3 and half Cynomel?

  • If 30mcg Liothyronine doesn't make you feel as well as 25mcg Cynomel yes, try half of each and see if there is any difference.

  • I am not sure what you mean by 'NHS' T3, because i have received Liothyronine manufactured by both Paddock Labs and Mercury Pharma on NHS prescriptions from my local Boots.

    Changing from Paddock Labs to Mercury Pharma, i immediately noticed a drop in effectiveness.

    My GP has now specified Paddock Labs on my prescription.

  • Thanks for that yousurname because I have changed from T4 actavis then mercury pharma and found it left a bitter taste in my mouth, so have gone back to actavis. When I got my T3 I noticed it was mercury pharma again, and I asked is there no other and they said that is all they do it in. Maybe this is why again, mercury pharma, I will ask for Paddock Labs this time and see if this helps. Thanks for that Info.

  • Mercury Pharma liothyronine is the only licensed product in the UK. Anything else is some sort of special - and costs accordingly. If you think MP is expensive, Paddock or Pfizer/King Cytomel is astronomic. Whilst patients shouldn't be directly affected by medicine pricing, it is a factor that is taken into account in many ways.


  • When my GP originally prescribed Liothyronine 5mcg, Boots dispensed Paddock Labs tablets. They are available on next day delivery. When I was in hospital (NHS) recently, I received Paddock Labs 20mcg tablets and not Mercury Pharma.

  • Well, I can assure you, you are not going mad. There are many reasons why you might feel worse on Thyroxine.

    One of the most common reasons is low iron. The NHS ranges are notoriously low so you want your iron and ferritin to be well within range - somewhere toward the middle of the range.

    Other issues may include low folate and/or vitamin b12. These need to be well above the bottom of the range. Folate should be above 12 and B12 above 500. Vitamin D needs to be in range too.

    It is also worth getting your cortisol tested.

    Selenium, magnesium and zinc supplements can also help. All of the above are important for the body to use thyroxine properly.

    If none of those work, you may need to try NDT (E.g. Armour) or t3. I felt wise on Thyroxine even when everything else was sorted out by am now much better on t3. It is difficult to find a doctor that will prescribe it though.

    I hope you find the solution.

    Carolyn x

  • Hi Carolyn, thanks for your reply. I am low in iron. At my last check I was 'in range' but sitting right on the bottom reference for iron, red blood count, ferritin and folate. I'm not sure about B12 as I had already started supplementing before the test. Right now I take all the supplements you mentioned and have been for about a year. I think I will push for an NDT prescription and go back for cortisol testing.

  • If your iron is low you will have problems with all thyroid medication so even if you switch to NDT you will still need to sort your iron out. I hope you get your NDT prescribed :)

  • Thanks, I didn't know about the iron connection. I'll see how best to get my iron levels up. I'm vegetarian which probably doesn't help. Hopefully the longer I stay off gluten the better I'll start to absorb iron and other nutrients. Sometimes I get dizzy thinking of all the interconnections of what influences what and wonder where to start!

  • Yes, it is a mine field!

    Taking vitamin c at the same time as your iron will help absorption. Taking via c before each meal may also help you absorb nutrients from food. Taking a complex will help your body to store iron too as it contains vitamin b2.

    If you are vegetarian you may be deficient in b12 too. This is common in hypothyroid patients anyway.

    I hope that helps a little.

  • Good luck with the NDT.

    I feel a lot better on it than Levothyroxine but only had a Vit D deficiency that has been addressed. I went for ThyroidS and followed the thyroid patent advocacy guidelines for slowly switching from levothyroxine to NDT. I feel my old self again after years of feeling like a sickly shadow of what I once was.

    I hope you get all the issues resolved, as raised by the very knowlegeable members here, to give NDT the best chance of working well for you

  • Hi Carolyn has these bloods done last May 2013 and my folate was 8.3 ug/L (3.00 - 20.00ug/L would you say that is low? Always tired and a myriad of other symptoms. My B12 was 667 ng/L (180.00 - 1130.00ng/L) and ferritin 99 ug/L (15.00 - 300.00ug/L)

  • You folate could be higher. I think 12 is a good minimum. Your ferritin isn't too bad but, with that range, you might want it slightly higher. Everyone is different though.

  • Hi some of your story parallels mine! I was extremely ill while taking thyroxine for 5mths Nov13-April 14; first @50mcg then 100mcg then reducing to 75mcg. I'm now not taking any thyroxine, as each differing dose made me more debilitated, with intense muscle &bone pain, exhaustion, horrible nausea, dizziness, vertigo + migraines. These problems were unremitting and I was taking pain relief every 4hrs plus anti sickness meds. Each day was an endurance.

    For the past 6weeks however, after being referred to an endocrinologist, I've been advised to stop thyroxine while further tests are carried out.The relief for my poor body!! While I can't say I now feel well, I do feel considerably better than at any dose ofT4. My symptoms now 6 weeks off thyroxine are small fry compared to how dreadful thyroxine made me feel.

    My main symptoms pre diagnosis were repeated bacterial infections, and I was fully expecting to be told I had type 2 diabetes after a range of bloods were taken by my GP. My fasting glucose and HbA1C were all fine but my TSH was 10. I hadn't really registered that I had any typical hypo s+s, but was bothered about the insect bite on my toe that was continually infected causing cellulitis.

    Anyway, I dutifully started the thyroxine 50mcg as prescribed, however after 2weeks of thyroxine I was bedbound. Before this, I managed to combine working in a demanding job with looking after 2 young children + this was often with an infected toe!

    I became more and more debilitated on T4, severe hypothyroid symptoms seemed to appear from nowhere and I felt as if I'd been knocked sideways. My toe infection also went crazy and I spent 3months on antibiotics with no real improvement. I persisted with the T4, after reading on various sites that often symptoms improve with time, it can be worse before it gets better etc and an increase in levothyroxine is often what's needed.

    I continued to feel dreadfully unwell at every dose of T4 and pleaded with my GP for a referral to an endocrinologist.( The dermatologist I was seeing re my toe was as mystified as the GP).

    The endocrinologist was very interested in the recurring toe infections and organised for me to have a short synacthen test for addisons firstly. It is possible to have a partial adrenal insufficiency apparently, which would make a person very ill if they were commenced on thyroxine without correction first of the underlying adrenal disease.

    My test results were fine so the endocrinologist then organised a full hormone profile and several 24 hour urine collections to test for Cushings disease. Some of the urine collections have shown over range levels of cortisol which may or may not be significant for Cushings. I'm now waiting to have a dexamethasone suppression test.

    The endocrinologist is also going to trial me on T3 alone in a couple of weeks,I do feel apprehensive about any thyroid meds after my recent experience but I know being unmedicated isn't a long term option and a meltdown may be imminent!

    If T3 isn't a happy experience I'm going to self medicate with armour or erfa. I'll follow what others on HU have done, order from an online pharmacy + start with a low dose.

    Increasing up slowly.

    I never thought I would ever be contemplating such a step!!

    Sorry for the long-winded answer, this condition is so confusing !

  • Rach,

    I was started on 200mcg T4 after TT for ThyCa and felt poisoned. Despite reducing dose in 25mcg increments to 100mcg I had became so ill over 18 months I was mostly bedridden and my vitamins were deficient and low.

    I stopped T4 and self medicated with T3 and there was a little improvement but not enough so I stopped all meds for 4 weeks in an attempt to detox. Brain fog, palpitations, tremors, fibro, COPD symptoms all cleared within 2 weeks. My TSH was 107.5 but I felt better than I had in years.

    When I resumed T4 symptoms started within 3 days so I added 20mcg T3 and that calmed everything. I'm now recovering well on 100mcg T4 and 40mcg T3 although I'm still as weak as a feeble thing but that will improve as I regain fitness.

  • Hi Clutter, I also found that all my symptoms cleared when I stopped T4. It is such a releif to hear that this is not such an odd thing. It seems that all the doctors and endo's I've seen either think that it's all in my head or just have no idea how to respond. I'm feeling much more inspired to be more direct at my next appointment!

  • That was quite a risk going up to TSH 107.5 I flipped at mine that went up to 29. I had withered it down from 100mcgs and taking T3 only, but doctor put me back on T4. Still unsure and trying numerous combinations. However after learning a lot I know that the gut is important and treating all underlying problems, I have some work to do yet, well I have been on this road for 20 years, so wish me luck......

  • Marmaris,

    My TSH is suppressed to prevent recurrence of cancer but I felt so ill I didn't care. The way things were going I wasn't sure I'd be around long enough to worry about cancer. I felt quality of life today was more important than worrying about what might or might not happen in 5 years. Happily it paid off and the T3+T4 combo is working.

    This is a great link from someone who has got her life back


  • Hi Rach,

    Thank you for your reply. It is so good to hear that I'm not the only one. Yes your story sounds just like mine. I also had repeated infections (although all viral) that would not shift. I also have two young children and know how difficult it is to keep up with life when trying to figure out how to regain good health! I would love to hear how you get on with various meds and endocrinologist. It sounds like you have a good endocrinologist. Each time I've seen them at my local hospital they spend about 10 minutes with me and tell me to keep on with T4!

  • Hi Kat

    Yes the endocrinologist I've seen is pretty thorough, but like others on here, he did ask whether I thought there was a psychological element to my problems with T4. Tried to keep my temper when I answered 'It's hard not to feel anxious and irritable when you're in constant pain +have vertigo/nausea 24/7 '!

    I've also had to be v.pushy ( doesn't come naturally)+ have done loads of reading, to get this far + to be taken seriously.

    Will let you know how I get on....Rachel

  • You may do better on T3 alone. On levothyroxine I was worse than before being diagnosed as hypo. Maybe your GP will give you a trial of T3 alone.

    If T3 alone doesn't suit you (both T4 and T3 are synthetic) ask for a trial of NDT which is more synergystic with the human body. Naturethroid or WP Thyroid are hypoallergenic if you have problems with fillers/binders. Armour is the original NDT. These contain all the hormones a healthy thyroid gland produces and many feel much better on them.

    I take T3 alone at present and am well and Naturethroid also suits me.

  • Hi Shaws, thank you for replying. I think after all the replies I feel much more confident to push for a trial on NDT. I'm very wary of T3 as I felt so awful when I tried it before but maybe, as you say, that was the combination of T4/T3. Thanks for the information about types of NDT. I think I'll do a bit more research into all of them so I can go back to the endocrinologist really informed about what I'd like to do next!

  • It is important to make sure your iron, ferritin and cortisol are good before starting t3. If any of them are low, start very slowly with the t3 or you may crash because your adrenals can't cope. In the long term, adding t3 slowly can actually help adrenal recovery.

    Carolyn x

  • Morning Kat,

    My situation was simillar to yours, I too am undermedicated but can only take a tiny amount once every 3 or 4 days.

    I do have Adrenal Issues (proven through the ASI test) not the GP. What is your pulse like?

    What I am doing now is reading a book written by a Dr who has recovered naturally & without Thyroid Medication, along with a great book on the adrenals and will be starting an adrenal friendly diet - so I don't have to have Hydrocortisone coz that doesn't agree with me either. Sorry not to be more help but I wanted you to know you are not alone, Thyroid medication causes me all sorts of nasty problems (in any form) but I can not be without it, but oddly enough the better I have felt the more the test results showed up that I needed more.

    Glad you have a good doctor - you have one of the lucky ones.

    Best wishes

  • Hi Kitten whiskers, thanks for your reply. It's really good to hear that it's not just me who has this problem. Could you let me know what books you're reading? I've read a couple of books but looking for recommendations too. What is the ASI test? My pulse is fairly slow at the moment but quite strong. I checked it regularly when I stopped taking T4 and it was steady and stable until I suddenly crashed out after a virus and it became quite weak.

  • Hello Jklm,

    The ASI test is the Adrenal Stress Index available from Genova Logistics - this test measures your adrenal Function & DHEA throughout the day with Saliva Samples, the test is done in you own home and sent back to them via a special carrier (as the Saliva needs to be frozen) This is not something a GP will support so would have to be done privately.

    The books I am reading at the moment are The Thyroid Alternative by Dr Nikolas Hedberg and also Are you Tired & Wired? By Marcelle Pick.

    I recently changed to west thyroid pure (this is Natural) and has been the worst medication for me - I feel awful, so I will be going back to T3 (Synthetic) - none of it is any good for me but that seems to be better than the others for me. If you did want more info on T3 I would recommened Paul Robinsons book - Recovering with T3, it also has lots of info about supplements.

    Your pulse seems to fit in with being under medicated, my pulse is always high and gets higher with the medication.

    Best wishes

  • You have a well rounded discussion of the difficulties in getting good treatment. A lot of it is due to the nature of the condition. So many different aspects are involved. This may give you an idea. It is one of 22 short videos I have been posting about low thyroid symptoms. I chose this one about progesterone but there are different topics for each one.

  • Hi Heloise,

    Thank you for posting the video. Do you have a link to the others you mention? Thanks, Kat

  • Hi Kat, Usually they are listed on the right side of the YouTube page. I'll post #1 and see if it is there. I do believe there is a lot to what he says are root causes of the condition. All important are stable glucose levels and stable cortisol levels to begin with.

    I guess after the video begins, on the bottom line of the box, there is a YouTube link. It says "watch on YouTube". When you click on that, you will see his other posts to YouTube.

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