Rapidly rising TSH while on levothyroxine - New here :-)

Hello :-)

I'm new to these message boards and to thyroid problems so any advice would be fab.

I started levothyroxine about 9 months ago due to fluctuating levels. My thyroid is routinely tested monthly due to another health issue so this was picked up quickly. I cant recall the exact figures but some months it was normal and some months it showed I was under-active (not drastically) hence started 50mcg of Levothyroxine.

I was tested for Hashimotos prior to starting treatment and the results were negative

Until October this dose kept things stable and within the number ranges but since then they have be as follows:

October TSH 0.06. Free T4 22.

November TSH 0.01. Free T4 26.

December 23rd TSH 16. Free T4 at 9.

January 9th TSH 81.8. Free T4 6.4.

So from November to now my TSH has increased from 0.01 to 81.8. My GP has rang me today and told me to up my medication from 50 to 150mcg.

Any ideas why the sudden increase? is it something I should be worried about? I don't feel unwell.

27 Replies

  • A quick question...

    Have you started supplementing with anything containing biotin since November?


    There is nothing wrong with taking biotin. It doesn't do people any harm. It's just that the testing process for TSH involves the use of biotin in some testing environments. And if the patient has been taking biotin as well the results for TSH get corrupted.

    The safest thing to do, so as not to affect blood tests, is to stop biotin for a few days before carrying out thyroid function tests. Patients can restart biotin immediately after testing.

  • Hello, no I don't take any supplements. I didn't know that about biotin though so thank you.

  • Most vitamin B complex contains Biotin ......so this is very relevant.

    Perhaps would be a good idea to make a dedicated post about this? Especially as lots of us take B complex.

  • The funny thing about this, though, is that "because" their testing assays "use" a biotin strain for testing, one would think the patient should be fasting from any biotin intake, which is very hard to do since it's found in nuts, avocados, seeds, beans, cauliflower, bananas, carrots, leafy green vegetables, tomatoes, raspberries, and mushrooms, etc etc.... it's found in many foods, IOW.

    LOL, this information is making Biotin supplementation out to be a bad thing, when it's really a wonderful vitamin in our nutrition. Seems to me what needs to change is the way they test thyroid! Wouldn't you think? This information seems to say thyroid people should avoid biotin? Or that the diet is skewing results. It also would say that one is hyperthyroid when they're not, so stop taking anything Biotin. This doesn't make sense for the person, but for the lab. :\ That's a quandary. Biotin is a good thing. It's in most BComplexes, too. So does this say all of our tests are wrong???? Do all labs use this biotin strain?

  • Marvelrus,

    The information simply suggests it may be better to refrain from supplementing biotin for a day or two prior to thyroid testing.

  • It would seem that refraining from foods, such as the ones I listed should also be avoided as well as any B Complex or any supplements, really, before you get labs. But how long? Makes me wonder if all labs use the biotin strain to test? What if ate a bunch of sunflower seeds the day before? They're a good dose of Biotin. Would it skew my results? But now that I know this, I'll be sure to cut back on biotin containing foods for a few days before labs. This is interesting.

  • Marvalrus,

    There is vastly more biotin in a supplement than in foods but cutting back a day or two before testing is probably sensible in case the lab uses biotin during analysis.

  • Sadly, only 'those in the know' will know. I wonder why labs don't state that requirement before testing? Maybe they are working on changing that? We'll never know......

  • Maybe you have asked the wrong question?

    It looks clear that TSH has risen because FT4 has dropped. So perhaps the question is why has FT4 fallen?

    If your thyroid is not responding to TSH by producing/releasing T4 appropriately, that could be the explanation at the superfical level. Why? That is the next question.

    Are you taking any supplements? Or medicines? Or even an unusual diet? As @humanbean so rightly said, biotin is a classic example of a supplement that interferes with some tests.

    The other problem is that we cannot know whether you other health issue is having an impact without knowing more about it. It is your information, we have absolutely no right to know, but if we don't we might miss something.

  • I'm not taking any supplements, biotin or eating anything unusual. I'm not on any other medication right now apart from levothyroxine. I have MS and have had a chemo type drug for this in the past. One of the side effects of the chemo drug is developing a second autoimmunity disease e.g thyroid problem. Obviously I have but that wont be causing the sudden fluctuating readings. Nor will having MS. I have full bloods run each month and have done for two years. All others bloods are / have been fine.

  • When the thyroid deteriorates, we often see reports of variability over time. This has often been used to suggest a diagnosis of Hashimoto's rather than some other cause. There are several theories including the possibility that the follicles break open and release colloid containing thyroid hormone. That would give rise to a variable, and uncontrolled, level of thyroid hormones.

    Eventually, when the thyroid becomes unable to produce enough new thyroid hormone, and the "stock" in the follicles runs out, hyopothyroidism is the result.

    Whether this is any sort of an explanation for you, I certainly don't know.

  • Thanks Helvella. I was tested for Hashimotos when first diagnosed and it was negative. It could of course have now changed. I guess I'm just confused as my readings in Oct and Nov suggested I was overactive and now they seem to have flipped the other way.

    What will be will be, I feel well so cant complain really.

  • Kedsheep, the majority of new hypothyroid in adults is Hashimotos. It seems like you're partly assuming you have it - you mention auto-immune disorder, and that's what Hashimotos is.

    The test can give false negatives, so it's not definite that you don't have it, and always worth a retest.

    If you don't have Hashimotos, it's a good idea to do more digging into what the cause is. Pituitary problems are the second most likely (a lot more rare), which can cause other hormone problems.

  • Can't add anything to the advice form the others, but I am a bit worried at the idea of you increasing your levo by 100 mcg in one go! That will put a terrible strain on your body, and probably make you feel worse. Normally, increases should only be 25 mcg every six weeks - at a pinch you could do 50, under the circumstances, but 100 in one go is just too much.

  • kedsheep,

    Agreed with greygoose - take it easy. the increase by 100 looks like a panic reaction rather than a considered response. Maybe you will need 100 (or even more!) but approach it more slowly.

  • I'm glad GP is increasing your TSH back to 150mcg. When you get blood tests for thyroid hormones, it should be the very earliest possible and fasting (you can drink water). Leave about 24 hours between your last dose and the test and take it afterwards.

    If you've not had B12, Vit D, iron, ferritin and folate ask for these as we can get clinical symptoms.

    Give the ranges when you post numbers as labs differ in them and it makes it easier to comment.

    Levothyroxine should be taken on an empty stomach with one glass of water and wait about an hour before eating. Food interferes with the uptake.

  • OK good to know. I'll start off on the 100 ones then and see how I go. My bloods are always taken in the afternoon and I cant change that as its dictated to me. I've never been told to fast. I have my vit levels tested now and then. My MS nurse is great and will run any test for me so I can generally bypass my GP. She did refer me to a endocrinologist some months back but as everything was fine I passed it by (I have enough medical appointments so try to avoid ones that are less priority). If the increase in levothroxine doesn't fix things I'll go see him.

  • In an ideal world blood tests for thyroid should always be taken first thing in the morning (before 9am), having fasted overnight and before the test, drinking only water. If, for any reason, this is not possible then clearly the idea of fasting during the day for a blood test in the afternoon is simply not feasible, and is probably extremely unhealthy.

    If you wanted to do blood tests for your own benefit rather than for your doctors, you could pay privately to be tested under the ideal circumstances. If this interest you, then ask about how it can be done.

    Since you have several illnesses the chances of you having ideal levels of nutrients would probably be remote. If you can get tested for the basics - iron, ferritin, vitamin D, vitamin B12, and folate, then getting those up to optimal will help your thyroid health as well as your general health.

    I've been thinking about why your Free T4 has dropped so dramatically, and your TSH has risen so much.

    A point about Hashimoto's - thyroid antibody counts can fluctuate. A negative result is not guaranteed to stay negative. Some people who have all the signs of having Hashi's never get a positive antibody test. There are several kinds of thyroid antibodies. For people who are hypothyroid the two relevant antibodies are TPOAb and TgAb. See this page :


    The NHS rarely tests antibodies for hypothyroid people at all, and when they do they usually only test TPOAb. There is a general belief amongst doctors that if TPOAb is negative, then TgAb must also be negative. This is not true, and I don't know where this belief came from. There are quite a few people who have posted on the forum who have negative TPOAb and positive TgAb.

    Since your Free T4 has dropped like a stone and your TSH has risen so much from December onwards, something has obviously changed. Some ideas :

    1) Has your brand of levo changed? Has the brand of any of your other meds changed? A different excipient or a different proportion of excipients in one of your pills could change lots of things if your body can't handle one of them. (Excipients are the ingredients in a pill that are not the active ingredient. They are needed to make an active ingredient into a pill.)

    2) There is a possibility that you have been given a duff batch of thyroid meds. This is probably the easiest thing to test. Ask your doctor for a prescription for levothyroxine explicitly naming a different brand of Levo to the one you've been taking since your test results went haywire. There are three different brands of Levo licensed for use in the UK. They can be found listed on this website :


    Do a search for "Levothyroxine". You will see the different makers and the dose sizes they produce in amongst the blurb in the table.

    3) Has your diet changed?

    4) Do you eat at a different time?

    5) Have you started taking your levo at a different time in relation to food?

    6) The pills you take for your other illnesses could have changed in some way that is having a knock-on effect on your thyroid meds.

    7) Have you had a flare up in one of your other illnesses or a viral illness?

    8) Have you had whiplash, a car accident, a bump on the head in the last couple of months? This could affect your pituitary or your hypothalamus which could dramatically alter the amount of TSH your pituitary produces.

    By the way, I'm not expecting you to answer all those questions publicly. (You can if you want to.) They are just things I can think of that could have caused your results to go whacky, and could provide clues as to how you might try to get them back to normal.

    Welcome to the forum. :)

  • Thank you for this. Really helpful. To clarify the only other illness I have is MS and thats been well under control for several years. I don;t take any other medication apart from Levothyroxine.

    I get my levo 3 monthly and on checking the last batch (which I was coming to the end of) it is a different brand to the one before. This may be the cause. The new batch of 150 mcg is the old brand so this may be more efficient. I cant think what else may of caused the huge spike as nothing else has changed. Even before starting levo my TSH were never that high. Untreated the highest was around 19 so 81 is unprecedented for me. I'm just hoping I dont end up overdosing on the 150 given my TSH was 0.01 2 months ago. I'll be having another blood test next week so it will be interesting to see what it shows. Thanks for all the replies.

  • The past 2 winters I have had a nasty virus with a cough that lasted ages. My thyroid was tested afterwards and TSH was around 10, though previously normal. It had returned to normal by July when I was tested again. Now after the virus it is 10 again. But I never alter the amount I take as taking more makes my heart race & pound & my feet tingle or go numb. It seems to me that illness has caused the variation. Perhaps if we were tested more often more fluctuations would be seen? I feel perfectly well as I am (now cough has gone) even though the levels are apparently wrong.

  • I do suspect we fluctuate more more than we know. I was first tested in 2012 and showed to be hypo then. Not tested again until a year later and tested normal. I only started having monthly blood tests 18 months ago and while some months have shown normal readings, others fluctuate quite a bit.

  • Thanks, I would be interested to know if anyone else has experienced this.

  • Can i just say what an amazing knowldege base everyone here has. It would put a GP and even (some) endos to shame. Thank you.

  • I second that!

  • Hello. I had another blood test yesterday and its going in the right direction!. TSH 52.40 and FT4 now in the normal ranges showing at 14. Still away to go but the med increase seems to be helping.

  • Still a remarkably high TSH for someone with in-range FT4. But, as you said, right direction.

    Thanks for coming back - could be valuable to someone in future.

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