Thyroid UK
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Advice fella's TSH is 6.8 he's taking Thyroid s but not told GP.He was to come back in 3 months for more long

GP tells him each time he will see how it is in another 3 months !!

Poor dear has loads of symptoms so started taking my Thyroid S

He is due blood tests on 22 july but wants to be free of the NDT so GP gets a true


Does anyone know how long it takes for it to completely leave your system??????



19 Replies

Blue99, Most will be out his system in 8 days after the last dose but very small amounts will remain in his system for +4 weeks.


If someone is hypothyroid then the half life of levothyroxine is reckoned to be about 10 days. So if he takes NDT the 35 mg of t4 in each grain will have reduced to 17.5 after 10 days, Then to 8.75 after another 10 days then 10 days later, (ie 3 weeks from first stopping) each grain would have reduced to approximates 4.5 mg. So how much is he taking? And you have to remember, this is only the half life of one grain after 3 weeks.

The day befores meds will need to be added on. And the day before that and so on....

Not really so easy to work out is it.... And the tsh lags behind too.

If he feels better, wouldnT this just be a good opportunity to see where he is on the medication, ie donT stop it. if his results come back and are satisfactory, he can just wait until his beaming doctor tells him there is nothing wrong and then he t tells the doc that there is nothing wrong because he has been self medicating. At least it would prove to the doc that no harm, and in fact some good is being done by taking meds.

CanT see the point of stopping and starting just to get the doc to agree he is ill.

Xx G


If his TSH is over 5 and he has symptoms I believe the guidelines say he should be treated. Couldn't he check this out with his GP? LB


I am confused about this aspect. I have a TSH of over 5 and symptoms, but the GP said we would only have a "trial" of levo and that was because I also have antibodies (both types I think) and have had them for nearly a year ( well, they have been in tests since then, could have been there before).

The GP would not have tried medication without the antibodies present.


Yes I'm not sure either but it is something I've seen written in responses from the admin team so I'm sure that must appear in guidelines somewhere. LB


Ive been on thyroxine for about 20 years, late 2011 i started to feel hypo symptoms returning, GP ran blood tests but although my ft4 and ft3 were low my tsh remained in range. it took over 4 months and 3 blood tests for my tsh to reflect what my body and ft3 and ft4 were screaming out. It turned out that I like many others were taking some faulty thyroxine called teva ( think thats how you spell it) anyway my point is it can take a long time for the tsh to reflect what happening, sadly most GP's only look at TSH. I believe this is based on the individual, so your fella's tsh may well respond much faster.

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TSH is a pituitary hormone and is normal in secondary hypothyroidism. Most GPs do not understand endocrinology.


The half life of T4 is 4 days, ie 4 days to build up and 4 days to go, the T3 contained within NDT has a shorter half life approximately 48 hours. It can stay in the receptor sites that long.

If your fellas TSH is high even at 6.8, Dr Hertoghe claims that nobody should be higher than 2 when he did his studies in Switzerland. How much is he taking? One grain, 2 grains? you have to be very careful not to take too little as the body will detect it and stop producing itself.

It seems totally ludicrous that he has to suffer so much just to please the GP but it's the norm in this country. If he comes off everything and is very ill the doc may prescribe T4 only but that's not a good combination to take as it lacks T3 and guided by the bloods it may not make him better.

II think I would find a GP that prescribes Armour thyroid and just come clean that he has taken it already. I think Thyroid UK have a list of doctors


Gismo, If something has a half life, it means that at the end of its half life, it has degraded by half, Then it needs the same amount of time to degrade again, then the same amount if time to degrade again and so on, until the amount left is too small to be measured..



Hi if you take T4 one day then by the 4th day it should be nearly passing out of the system. Say you take it for a month and then stop, after 4 days it is nearly gone, however, there are always some remnants for a few months. I really wouldn't worry, the blood tests are inaccurate anyway so why not find a doctor that will look at symptoms, uses NDT and has a good approach to thyroid treatment.


If you wish to have a list of sympathetic doctors, email

I think Galathea's advice is good. If you stop taking thyroid hormones, it can backfire in that you could feel much worse and it might take longer to get back to a reasonable state of health.

Before the blood tests were introduced, we were prescribed NDT and you had to gradually increase it until you felt well and all symptoms relieved. As his TSH is so high, he has to increase ThyroidS (gradually).


From my experience I have found that although the T3 is out of the system by four to six days, the T4 remains for much longer. I have also found that it takes even longer to get the TSH back up, and if his doctor is going to go by TSH only he might find that it is lower than the last test and therefore doctor might suggest waiting to see how a further test goes in three months. Also, although round about 5 is said to be the top of the range, a large majority of doctors are not treating first time diagnosis until it is 10.

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I can understand why you want to get the doctor to diagnose a thyroid problem and start treating it - the NHS pills and blood tests are free. If it was me I would leave 3-5 days drug-free before the blood test, then get it done first thing in the morning without eating breakfast. By then he should be feeling all the old symptoms returning.

Gismo333 is right that when you begin taking thyroid meds your own thyroid tends to produce less - it's as though your thyroid was being flogged really hard before you took the meds and takes a bit of a break when you start medicating. I think that's why you experience symptoms pretty quickly once you stop taking the pills. This should work in your favour in this situation.

Did any of the NHS blood tests check for antibodies?


I have had experience coming off my meds 3 times to have RAI. The official line is about 10 days for T3, and I can't remember exactly for T4, it's in the region of 5 weeks. This is for very hypothyroid people, you're expected to have a TSH of 40 or more on the day of the scan!

I've only experienced with this is for T3, as I think with T4 it isn't considered reasonable. Although there is an injection you can have to mimic the effect of being off the T4.

I actually found the first week off T3 didn't feel too different, then I would get a very sudden crash. When I had my full on RAI treatment, with a week in hospital, the extra week was the killer.

Sorry, too much information. I think I agree others that this can't be done. You're already actually too late for him to take 5 weeks off, and it may not produce accurate results even if you could, because his body will be impacted by that shock.

Also I think it will not be good for his health to chip and change like that - you need to be gentle with your body. It is definitely possible to get worse, lots of additional problems are caused by the body struggling to cope with being hypothyroid, adrenal fatigue, vitamin deficiencies, and goodness knows what else. Don't play with his health!

I don't think you have much choice but to come clean with the doctor. Personally I think you did the right thing to self medicate. People in your bf's position are left in limbo by doctors possibly for years. You might get repercussions from the doctor, but if they weren't going to help him get better anyway, they aren't really on your side!


6.8 is way too high. Anything over 4.2 and he should be on medication. What's his GP playing at?

I would come clean and tell the GP that he has been self medicating. You have the right to complain to the practice if you are not happy.


a true reading is not important. He is already hypo according to his TSH, severely so and there is no reason to make your husband more ill, so some idiot doctor can get a blood level. It is unsafe to be so hypo. If this doctopr hasn't treated him by now, he won't and doesn't know what he is doing. Are you planning on pulling your husband off his meds, every 3 months then? Makes no sense. Stay on the meds and find another doctor.


Thankyou everyone for your advice,he takes 1Thyroid S a day ,he also takes tegretol as well so I think it is important his GP is aware how bad he feels and what he is taking but GP seems to want him to get to a higher reading again before he will treat him.He is very headstrong and has decided that he is going to stop the NDT and get the bloods done regardless,he now realizes that he may not have needed several medications over the years that the doctor has prescribed for his moods!



T4 half-life is about 7 days. Many practitioners say that you haven't reached a steady-state until 5 half-lives (35 days) have passed.


All my sympathy -when you feel so poorly you will do almost anything to get better. Your GP is leaving him feeling poorly for all that time is shocking I know!! TSH ranges vary from area to area -so I would get print out and look at what the range is ( figures in brackets.) In my area TSH normal range goes up to 4.8 -anything over that is abnormal and the GP may consider prescribing levothyroxine. Most GPs will look for a TSH that continues to be high -ie more then one blood test in a row hat is high or a pattern showing a gradual increase in TSH resulting in going over the range. They should also be looking at clinical signs and symptoms -but hey many for get to do so or don't know what they are looking for....sadly! Te reason why they look for a continuous period of raised TSH or rising TSH is that your TSh can rise temporarily when you have an infection.

Sounds like your BH wants a diagnosis and am afraid to get that from his GP he will have to play the game of not taking the meds to demonstrate that his TSH is consistently out of range or consistently increasing. A friend of mine has been borderline for years and this time she was well over -sadly her GP would not prescribe but ordered another blood test to see if it is still too high -he may then giver her a trial of Levothyroxine.

Wishing you the best and most importantly that your BH gets the treatment he needs. xx


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