I have been taking 50mcg of Levothyroxine, along with 10-15mcg of Liothyronine/T3 (5mcgx2-3), and had labs done about 1-2hrs after my morning dosage(s). My results were:
TSH - .24
FT3 - 2.8 (2.3-4.2)
FT4 - .9 (.8-1.8)
My PCP initially said based on labs I had mild hyperthyroidism, though my symptoms are still present.. I believe he based the initial theory on my TSH alone, which I've encountered before, but really honestly just want to feel better. I've taken 5mcgx3-4/day for 15-20mcg total and felt more energetic, less cold, improved mood/cognition and so forth.. My question is, based on the labwork shown here, would it be fair to ask for a dosage increase on either the Levo or T3?
I did meet with a Cardiologist with knowledge of thyroid meds/function on a separate matter more recently, and he reiterated the importance of treating the symptoms of hypo along with focusing on the free and total levels of T4/T3 when adjusting dosages over the TSH, which to be honest I fully agree with.
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Kc885
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And I should also note, the labs were as stated drawn 1-2 hours after ingesting my morning dosage of Levo and 5mcg of T3, which I've read will alter free hormone levels.
You should have the blood taken half way between dose, but also allow four hours after a dose so that the hormones have time to bind to their transport proteins. Otherwise the free hormone results will be misleading.
Your TSH is too low for these hormone levels. This i because the pituitary thyrotrope is under performing, not because the TSH is suppressed. I would switch to 10 mcg L-T3 twice daily and increase your levothyroxine to 75 mcg.
You regularly suggest this halfway approach. Afraid I flat out disagree with you.
If you wander round advice regarding blood tests in relation to numerous other medicines which have a narrow therapeutic range (although levothyroxine itself is excluded because it almost never kills us if we overdose!) such as warfarin, every one said that blood tests should be "trough" tests - before next dose.
In some, levothyroxine peaks do not occur for three hours or longer after ingestion.
If we try to hit a level which is changing, as in a slope on a graph, then even a short time difference can make a significant difference. We don't fully understand all the factors which affect how our FT4 levels vary after ingestion so making allowances is impossible.
Different drugs have different purposes and modes of action. If you have an anti-cancer drug you need to maintain a minimum dose to stop the cancer growing, even if there are unpleasant side effects. The same would apply to warfarin, it's no use preventing a fatal stroke for half or three quarters of the day.
Thyroid hormone receptors need to be saturated for several hours before expression takes place. Since we are measuring free hormone levels it's important to leave four hours for the hormone to be absorbed and bound to transport proteins. An hour or two after ingestion of liothyronine the free T3 levels are very high, fortunately this does not cause a metabolic spike due to the slow response of the thyroid hormone receptors. This is why liothyronine (twice daily) does not cause the varying clinical response that endocrinologists often assert. The response to liothyronine is reflected by the 'area under the curve', essentially the average level of free T3. The best approximation we can get is to draw the blood a little before half way between two liothyronine doses but at least four hours after the latest dose. For patients on liothyronine twice daily drawing the blood about five hours after the last dose would give a fairly optimal accuracy. In practical terms anytime roughly midway between doses will be good enough.
These comments apply primarily to T3 containing medicines, liothyronine or NDT. Levothyroxine has a seven-day half life and so leaving an extra 12 hours would only introduce a 5% inaccuracy. It is wrong to imply we don’t understand how fT4 levels vary after ingestion of levothyroxine, the pharmacokinetics of levothyroxine are well understood and documented. It is also wrong to suggest that by leaving a long time after ingestion there is a through and not a slope. The nature of half-life decay is that there is always a slope. Whether the number changes from 10 to 7 or 1.0 to 0.7 the decay rate is the same.
I know endocrinologists and GPs are reluctant to prescribe if thyroid hormone levels are high and sometimes patients have no choice but to fiddle the blood test results by leaving an inappropriately long time between dose and blood draw. If you want an accurate blood test you should take the blood about half way between doses. If you want a fiddled figure you can leave a long time, or even knock up some numbers in a Word document. In either case you will not be getting useful data for your own use.
I’ve never seen a recommendation that 24 hours is left before taking blood for a thyroid function test, nor any research to justify it. Having the blood taken early morning is a bad idea. It gives a higher figure but is when TSH is on a steep slope and it is most unlikely that participants in thyroid research studies have their blood taken early morning.
One can fiddle blood test results. By far the easiest way is to type the numbers you want in a Word document - cheap and painless. Otherwise, if you want to produce a false high TSH: -
1. Have the blood taken at 3 am.
2. Run at least a few miles to the surgery.
3. Don’t eat anything for a long time.
4. If you are a menstruating woman have the blood taken mid-cycle. (This has more effect on TSH than any of the other fiddles.)
It comes down to the objective of having the blood test, is it to tell you what your hormone levels are or to mislead a doctor? I'd rather get the truth and argue it out with the doctor. Fiddling the results confirms doctors' impression that patients get better with 'normal' hormone levels and is a disservice to fellow patients.
Both abstracts below point out that time is important and needs to be taken into account. As the profile of TSH and FT4 (and FT3) consequent to taking thyroid hormone medications is variable from one individual to another, I cannot see how an individual doctor could accurately take account of the timing of the blood draw with respect to ingestion of the thyroid hormone. Neither abstract - nor any other I have ever read - gives any guidance on how to take the timing into account. I am quite certain that there is no formal guidance on how to do so in papers in English on PubMed.
Further, the vast majority of thyroid research appears to take no account of timing. Any conclusions drawn from such research which would be upset by changes to timing need to be reconsidered.
Thyroid. 1993 Summer;3(2):81-5.
Thyroid hormone levels affected by time of blood sampling in thyroxine-treated patients.
Ain KB1, Pucino F, Shiver TM, Banks SM.
Author information
1 Veterans Administration Medical Center, Lexington, Kentucky.
Abstract
Patients receiving exogenous levothyroxine are reported to have higher total and free serum thyroxine levels than euthyroid controls. This may be an artifact of the serum collection time. We explored the effect of collection time on serum levels of thyroid hormones in outpatients receiving levothyroxine for replacement therapy (26 patients) or suppression of thyrotropin (25 patients). Blood samples, obtained during regular clinic visits (random samples) and at more than 22 h from ingestion of levothyroxine (trough samples), were assayed for total and free thyroxine, triiodothyronine, and thyrotropin. Four athyreotic patients on levothyroxine therapy had serial blood sampling over 24 h. Compared to corresponding trough samples, random samples had elevated total thyroxine levels in patients receiving replacement (8.1 +/- 1.2%, mean +/- SE, p = 0.0001) and in patients undergoing suppression (8.8 +/- 1.6%, p = 0.0001). Free thyroxine was increased by 12.7 +/- 2.6% (p = 0.0003) and 14.5 +/- 2.3% (p = 0.0001), respectively, compared with trough samples. Thyrotropin levels were 18.9 +/- 6.8% (p = 0.003) lower in patients receiving replacement and triiodothyronine levels showed small or no changes. Time-course analysis showed that free and total thyroxine levels remained significantly elevated above baseline for 9 and 5 h, respectively, after a levothyroxine dose. In conclusion, there is a transient increase in thyroid hormone levels for 9 h after an oral levothyroxine dose. Accurate assessment of thyroid hormone levels in patients receiving levothyroxine therapy should take this into account. This has greatest significance in selecting minimal levothyroxine dosages for suppression of thyrotropin.
Diurnal variation in TSH and free thyroid hormones in patients on thyroxine replacement.
Sturgess I1, Thomas SH, Pennell DJ, Mitchell D, Croft DN.
Author information
1 Department of Nuclear Medicine, St Thomas' Hospital, London, UK.
Abstract
Eleven patients with treated hypothyroidism were investigated to examine the effects of time on their thyroid function tests. Each patient was clinically and biochemically euthyroid on once daily thyroxine replacement therapy, taken in the morning. TSH followed a diurnal rhythm with a peak level at 23.30 h and a trough level at 14.30 h. Four subjects had TSH trough levels within the normal range, but with peak levels outside this range. FT4 and FT3 levels fell from their highest levels some three hours after ingestion to the lowest levels just prior to the next dose. This study shows that there are significant time-related variabilities in TSH and thyroid hormone levels in treated hypothyroid patients. This should be taken into account when interpreting results of their thyroid function tests.
It’s difficult to comment on these two studies without seeing the full papers but they seem to be competing in a state the blinking obvious competition! They essentially show that fT3 and fT4 are higher just after taking hormone and lower just before. The second one shows that the diurnal TSH variance is preserved in patients taking levothyroxine (presumably at non-suppressive doses). Studies that fail to control timing of taking of thyroid hormone and drawing blood are impaired, it does drive me nuts that such simple issues are not considered. Fortunately, many studies will be OK as both the control and study groups will by chance have a similar mix of timings. You are right, there is no guidance for doctors or patients about when to take hormone prior to a blood test.
Half-life elimination times will vary between subjects and tend to shorten with higher doses as the body strives to eliminate what it sees as excess hormone. Thus, the longer the time between dose and blood draw the greater the margin of error. This error is increased in patients on higher doses which is unfortunate as more precision and care is needed with higher doses. This is why I’m so keen on trying to take the blood mid-way between doses.
Apart from the running (fast walk), I've done that (but 8am) and still got a low TSH (but I have secondary hypo). Actually results were the same as eating properly the day before and driving to the hospital, so I'm not convinced.
Running and starving can raise TSH in most subjects but we all differ. In your case had you artificially got higher TSH results you would miss the fact that your pituitary thyrotrope is under-performing.
Jim, what you don't seem to understand is that, for the majority of us, arguing it out with a doctor is an impossibility. A), the don't listen, b) they think we're all morons, anyway, and if we're women, we're just moaning, exaggerating, attention-seeking hypochondriacs! I bet no doctor has ever dared to treat you like that! C) we're so brain-fogged that half the time we don't even know what day it is, and d) not many of us have your education or capacity for learning, anyway! We're just ordinary people doing what we have to do to survive. And, if that means lying, cheating and misleading doctors, that's what we'll do! All the hypothesising in the world will not get a diagnosis or dose increase out of a doctor who just sees you as an over-weight Barbie doll, with the brain of a slug - which is the way most doctors see woman.
Oh, and even worse if you happen to be of normal weight and reasonably attractive, because then there can't possibly be anything physically wrong with you, you're just a looney! Here, take these anti-depressants, and don't worry your sweet little head about a thing! Pft!
I appreciate some patients have to fiddle the results. What concerns me is that advice is given to always fiddle the results, sometimes even when the patient is self medicating. In the long run it will propergate the idea that all patients get well with normal hormone levels because that is the results you give the doctor. I did get told I couldn't possibly be hypothyroid because the blood tests said so, in spite of severe hypothyroidism that was obvious. Actually he was a very nice endocrinologist, he just couldn't see beyond blood tests.
Yeah, not quite the same as being repeatedly treated like a retarded goldfish, though, is it.
To be fair, people on here normally say that when you're self-treating, the important thing is to always do your labs at the same time of day so that you can compare them, to mark your progress - or lack of it - and that the TSH isn't important unless you're going to show these labs to a TSH-obsessed doctor. You can't really expect people to go into - or even to absorb or understand - anything more complicated than that, when they have a disease that affects their thinking. We do the best we can, but I often have the feeling that you do your best to under-mine all we're trying to do. Perhaps you also consider us to be retarded goldfish...
No. I'm not sure how I would distinguish a retarded goldfish from an intelligent one ;-). I'm trying to be simple, just have the blood taken half way between doses. Whatever the purpose of the blood test there will probably be a time in the future when you wished you had credible numbers. A large number of patients have wasted hundreds of pounds on assays that have produced meaningless numbers. Also we can't comment on patients blood tests if the test has been invalidated.
I totally agree with greygoose, I have been treated exactly like that for years! and if I hadn't come looking on here when they changed my brand of Levothroxine (:Teva ) and became even more unwell I would still be believing The GP and still be almost bed bound , i narrowly escaped a label of Fibromagelia But thank god I found this site else I would of maybe even killed myself as life was c*ap
Not one GP out of many GPs that i saw in 12 years ( about 10 or maybe more of them ) were taking me seriously! I was dead in the head people said I changed the year i went Hypo ! GPs wouldn't listen to how I was actually feeling and I said I felt hypo,
I was sent to a shrink again as I was in my teens! a total fruit cake, given anti depressant after anti depressant to shut me up, mong me out ! but i would try and go back as I wasn't depressed i was ILL ! depressed s how i was when i lost my mum, my dad, my dog, ! thats what GPs thought I was making it up so i must be !! thats what i have in my notes, orim sure all us hypo ladies have heard , its your age, it s that time of life your pre mental, your are pre menopause your going through change of life...your over weight because you eat too much ! just diet exercise more. I was on less than 1500 cals per day and still fat, I was even sent for Alziemers test as my memory was shot to bits and who wouldn't be if they were being treated wrongly ! or it was this it was that it was everything but my Thyroid,, it happened to me with GPs in my teens when i was hyper as well I missed my teenage years through ignorant GPs Hypo just 40, I got antidepressants shoved down my throat on both ,
I was asked if i was using drugs when I was hyper , GPs failed to think my protruding eyes were my thyroid ! then when eventually they found out I was severely hyper, I was near on dead....Thyroid storm, lots of apologies by all Gps their excuse was it doesnt normally happen till woman are in their 40s !!! ! by then it was too late I missed those years..
Same thing 40s are supposed to be best years of your life , did i enjoy them no because I was hypo and given Levothyroxine and told that was all I had to do was take that for rest of my life and nothing would change, well was all downhill from then on !I I would be well on them , nothing explained, I didn't have internet those days so didn' t even think to read up on it, ,I believed and trusted the GP but he never believed in me!
,, I don't understand all the science behind it and how most of it works, but GPS should know the symptoms should we get them and treat us accordingly but they dont they go on that science and can not think outside the box ! ! they should also trust a patient who is constantly saying they feel ill, tired, HYPO.. so if these people are getting a better result so the GP does not reduce the dose who can blame them, Most of us are left brain fogged because of GPs ignorance and the patients feel a little more than fiddled by the GP so if they fiddle him back to get the right dosage so best ! good luck to them its hardly a con when all the patient needs is not to be under medicated!
Im a bit better now as found a decent Endo who actually llistened to me, yes thats right listened and wasnt baffled by the science of it all he went on how I was feeling, thats how they all should treat us , Hypo affects everyone differently, not only does one drug never work for everyone the same bloods definitely won't,, and the result is because he listened to me as a individual I eventually have got better treatment which I should of had the minute I complained over 12 years ago not palmed off like i have been for years !
I feel so much better , I can get up I can do stuff I feel a bit more human, I feel happier. is not thanks to my Blood tests or the crap treatment I have had for 12 yrs...I found out why i was feeling so bad from real people on here who have helped me find out more about why I was feeling S**t .. Thank you to them they know a lot more how it feels to be Hypo than people filled up with numbers on bloods !
So sorry to sound rude here but it does appear to me all these people who know all Science/Math of blood results really proves thew Know jack Sh*t about how being Hypo makes people feel and how crap Levothyroxine is "the one for all drug" that is supposed to work for everyone! ,Rarely do I see someone compliment GP for listening or believing us the patient , They ignore the fact that having T3 checked may stop people losing part of their life !
.. Real people on this site , not just blood results! that do not match how you feel ....its all those blood tests that have left me and people like me un treated So all what you have written Jimh111 mean Jack if you do not feel healthy , I keep seeing you crop up, are you qualified in knowing all about the Thyroid ? you have dissed the Di02 test , who are you what do you do ? are you working for pharma or something as see you failed to answer when asked before Maybe I have missed it but on that occasion you completely ignored that part of the question!
You maybe medically trained, I don.t know you keep trying to baffle us with all these big answers and that you know everything and your way is the correct way ?? what do you do ?
By the way in case you hadn't read about it the TSH is only really is fit for diagnosing Hypo as quoted by the man who invented it )
Sorry I have struggled all life with thyroid and when you said people are fiddling the blood tests. I just got angry and wonder who are you really ? what qualifies you to tell us on here ? Just asking as you seem to think you know it all
Pascha1, I am a patient, not medically trained, no link whatsoever to any medical or pharmaceutical organisation. I was severely hypothyroid with mid interval fT3 and fT4 and a TSH of 1.0. I was an excellent computer programmer, could assimilate a 1,000 line of code program and work out a modification and restructure it in my head. One day when I was hypo I was going to the local shops for a newspaper and loaf of bread. I had to write it down on a list, I could not remember. I was forced to give up my job. Financial consequences amounted to over £250,000 in terms of lost income and a final pension that was half what I expected (nerdy, but I studied maths). The personal effects were greater than the monetary, I became irritable and very insular and suffered from many symptoms. I was diagnosed by the late Dr Skinner and required high dose liothyronine, up to 120 mcg at one time. I’m now doing my own research into the cause which I believe is due to endocrine disrupting chemicals. I’m trying to get a paper published but there is immense prejudice against patient submissions.
I’ve never dissed the DIO2 study, I’m a fan of the team that carried it out, they have a high standard of scientific rigor. As I’ve mentioned in other posts the DIO2 polymorphism doesn’t explain the major symptoms both you and I had. And in any event these symptoms would fully resolve if you replace the 6 mcg of T3 the thyroid normally secretes. The other issue is that if you insist on the DIO2 polymorphism being the cause you only help the 16% of the population who are homozygous for the polymorphism – the other 84% are consigned to the dustbin.
I do feel a little aggrieved. In reply to Kc885 I simply said that they should leave at least 4 hours between a dose and having the blood taken preferably about half way between doses. This gives the most accurate result. I also suggest that based on their symptoms they might try increasing both their levothyroxine and liothyronine a little. This to me is perfectly straightforward and reasonable.
I know some patients want to fiddle their blood tests so that their doctor will prescribe. They might get the prescription, but it reinforces the doctor’s perception that patients get better with their hormone levels in their respective reference intervals. This strengthens the blood test rules dogma.
It may help the patient, but it is a short term self-centred approach. If anyone wants to advocate this approach it would be fairer to say: ‘taking the blood half-way between doses will give the most accurate result but I find doctors will only prescribe if they see ‘normal’ hormone levels. We can achieve this by leaving a long interval between dose and blood draw … etc.’. It’s unfair to suggest they take actions that distort the blood test results without making it clear this is what they are doing, and the blood test result will be meaningless.
You now have a very helpful endocrinologist who is prescribing liothyronine and it is working. I’m not certain but I think they are doing this even if your thyroid hormone results are not all within their reference intervals. That is, they are treating the patient and not the numbers. This is what needs to happen. If we fiddle the blood tests we support the doctors who are TSH obsessed and undermine the good doctors like yours who treat the patient.
But Jim, if we do it your way, that will leave thousands of hypos un-medicated and suffering. The majority of GPs do not have the training - nor even the intellectual capacity - to understand all you're saying, there. And, it's them you need to tell all this, not us - we know the system is all wrong and that you should treat the patient, not the numbers - but that very, very rarely happens. As I've said before, you were very lucky to get diagnosed by Dr Skinner, and nobody is ever going to be that lucky again.
I understand what you're saying about getting a paper published - and I applaud you for trying - but how many doctors will ever read it even if it is published? What else are you doing - can anybody do - to get through to the medical morons that destroy our lives? You're not being practical. You live in an ideal world that the rest of us can only dream of inhabiting. Meanwhile, we have to struggle on to get to work, bring up the kids, put dinner on the table. You are seriously misleading patients into believing that all they have to do is explain all this to doctors and everything will be alright. You obviously haven't met some of the doctors I've met! For all their medical training, they have the intellect of a dead goldfish, and yet believe that they are all-knowing, all-seeing - in other words, 'god'! - and that the poor creature suffering in front of them is nothing more than an attention-seeking peasant wasting their time. You've got to be more realistic in the things you say to people.
Oh, and as to patients 'fiddling' the blood tests, wouldn't you agree that doctors do this too, by actually telling their patients to take their medication just before the test? And, on the subject of 'fiddling', what about doctors that give a 'three month trial' of levo or T3, on a dose that obviously isn't going to help anyone, and when it doesn't help, informing the patient that it 'obviously wasn't your thyroid, then'. Isn't that the worst type of fiddling? And doctors that insist that it doesn't matter what time of day you have the test because the TSH is always the same, yet reject FT3 tests on the grounds that the FT3 fluctuates throughout the day. And, I'm sure there are many other examples which don't come to mind, at the moment. We, the patients, have to play them at their own game, down here in the mud; whilst you, the intellectuals, fight them on a higher plain. What we do may not give the 'most accurate results' - but then most doctors wouldn't recognise an accurate result if it bit them on their up-turned noses - but at least we get to survive to fight another day - and with a clearer brain, qui plus est!
Patients do get help from doctors but not enough. Maybe I can ask that when recommending these strategies it is made clear it is designed to give 'good' numbers rather than accurate results. The patient then has a choice. As it stands they are sometimes given the impression they must not take hormone for 24 hours or so in order to get accurate results.
That is often said. But, typing the same thing over and over again gets so wearisome, that it is often over-looked. And, before you suggest copying and pasting, I don't like that idea, because I like all my replies to come across as personal, and not one-size-fits-all.
Your results will definitely be skewed. It is recommended that 24 hours elapse between last dose and test and take it afterwards. Your doctor will then either reduce your dose unnecessarily as they are only interested in the whereabouts of the TSH.
For T3 and NDT we usually suggest leaving a 12 hour gap. For Levo, leave a 24 hour gap between last dose and taking blood for testing.
Jimh111 is in a chorus of one and has different ideas about timing of testing and dosing when compared with almost everyone else you will read on this forum.
The recommendation is that 24 hours elapse between dose and test and that the blood test is the earliest possible.
Thyroid hormones should be taken either first thing with one full glass of water and if having a blood test, this dose should be missed and taken after the blood test otherwise the results will be skewed and may mean you don't get an increase you need, or even a dose reduction. Some people prefer taking their dose at bedtime as long as they've last eaten abut 3 hours before with one glass of water. If so, and having a blood test next a.m. they miss this bedtime dose and take after test and night dose as usual the same day.
Doctors only take notice of the TSH and I don't think they know they realise that the TSH is highest early a.m. and drops throughout the day.
Yes you are so right!! But that’s an NHS Endo and a private Endo both saying FT3 2.1 (3.5-6.5) and FT4 7.0 (9-24) not Hypothyroidism as TSH too low at 0.1 (0.3-6). I do not know how they get away with it. They do not understand what Hypo does do people. One day it will change for thyroid patients. Thank you. ⭐️
Oh my goodness I’m amazed is your GP perscribing t3 ??? please advise me who your gp is . This is fantastic . On the question of your bloods not at all your just about ok . The Tsh I feel ok on is always less than 1 but GP’S are driven by the ridiculous nice guidelines rather than patient well being : and actually all your results are the Lower end normal so it should be ok to ask for. A small increase .best luck to you and I hope you feel better soon .
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