TSH blood draw time?

In order to achieve the lowest TSH reading on our thyroid blood tests, we are always advised to get a blood draw very early morning, on a empty stomach without our meds.

Why then on the Thyroid UK website does it state...........

TSH has a circadian rhythm (24 hour cycle) and levels peak between midnight and 6am?


Surly this would indicate bloods were better drawn in the afternoon when TSH levels must drop?

I'm very confused,


14 Replies

  • You've confused me, now, Flower! We want our TSH as high as possible. That would be between midnight and 6 am. Difficult to find anything open at that time - even when I was in hospital they didn't take blood til 7 am, So, we have to get it done as early as we possibly can - which for me is 8.00, but for some people as late as 9.00.

    In the middle of the afternoon, it would be at it's lowest. So, your doctor would say, wow! Look at that low/suppressed TSH! I'm going to lower your dose. And that is not what we want to happen, is it?

    Also, TSH lowers after eating. So, to get your TSH as high as possible, Don't eat breakfast until after the test, and get your blood taken as early in the morning as you possibly can. :)

  • greygoose,

    Confusion is not something to be taken lightly and I apologise profusely for being the cause of it.

    You are so right and I just don't know what happened to my brain this morning.

    I hope I haven't muddled to many others peoples.


  • It can be confusing so don't worry as long as you know. We have to remember so many things in order to try to get well just because the doctors are following their guidelines, which can harm many who are on this forum.

    We have to be vigilant whereas we just want to take our meds, feel healthy and well and not need to bother about timing, doses, trying to explain to GP how we are not progesssing. :)

  • It's OK! I did exactly the same thing this morning. lol Half awake, couldn't remember something I'd said in the middle of the night, and denied having said it. lol No, I'm sure it won't confuse others. Don't worry. :)

  • Denial is always the best option and I would deny ever writing this ridiculous post if it was not already out there for all the world to view.

  • lol

  • I'm glad you wrote it. I'm new to this forum and not very well read. I've been on levo for years now and blindly followed the doctors advice - until now! They reduced my does from 200mcg to 150mcg a few months ago and I've gradually got all my old symptoms back, plus more. I'm going for a blood test on Friday morning so will make sure not to eat or take meds first.

    I'm now intrigued over all the different meds, tests and problems on here - so I shall continue ploughing through all of your interesting posts😀 until I 😴

  • Hello Slimjac,

    Thank you and just make sure you have your blood drawn at the earliest morning appointment when TSH is at its highest.


  • We are advised as early as possible as we want our TSH to be at it's highest level, because if it is, in the GPs eyes 'too low' they will adjust our dose of hormones. That's not good.

  • Hi flower. I'm sorry I can't actually make sense of this for you: I have vertigo / disequilibrium episode at present. However, when I read this I remembered seeing charts showing the daily rhythm of TSH, T4 & T3.

    Try here



  • crabapple,

    These graphs are really interesting and worth saving for future reference.

    Thank you for advising me.


  • Thanks for asking the question,Flower, because it has made me realise that I had my bloods done at 6 pm (TSH 4.9) and now realise the importance of early morning bloods. My next appointment is 8.40am so will hopefully be higher and can at last get some treatment. I have, however, decided to make an appointment every week, as they Were making me wait 3 months. I have suffered 7 years and been made to feel like a hypochondriac nuisance, so now I am going to be one! I am cross because it was 2008 when my first high ths blood test was recorded and nobody told me or did anything about it, even though I was symptomatic. Grrrrrrrrr... Sorry having a bad day!

  • Sometimes Tellybelly, we have to make a nuisance of ourselves to get heard.

    I hope you get some answers soon.

    Seven years is an awful long time to wait so make sure you have vits & iron checked too as they could be deficient now through being left unmedicated for so long!

    Happy days,


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