Blood test timing

[Bookworm63]

Hi all you clever folks out there, I’ve upped my medication of liquid thyroxine in the last few months from 50 to 75mcg. I did it without GP’s consent but I was feeling so hypo and tired and although my last blood test results were within range (TSH 2.35), I knew an increase would help. I was going to back to GP and tell him of increase which I had done slowly and gently and ask for blood test. I have felt much better which is good but as it happens the GP surgery have now requested that I have my annual blood test anyway. My question is that I can’t get an appointment early in the morning at about 9 the appointment is for 12.20pm. If it had been earlier I wouldn’t have taken my daily dose of Levo until after blood test. Given the circumstances so you think I should take Levo at my usual time, (8.00am), or after the blood test 12.20pm)? You’re advice would be much appreciated. TIA 😊

[SlowDragon Administrator]

Don’t take levothyroxine until after test

TSH will be lower mid day than at 8am

Ideally you would wait few days longer for an earlier test

[Bookworm63 in reply to SlowDragon]

Thank you SlowDragon, that is what I thought would be best but wanted to check. I couldn’t get in for a blood test for next week and Tuesday the following week was the earliest. I did ask for an earlier one later in the week but they didn’t have anything so went for the Tuesday one. I wanted to know my numbers now but I did want to get as accurate result as I could. Would really have preferred an earlier one but you just have to take what’s going these days.

[Stourie in reply to Bookworm63]

I once had to wait 3 weeks for an early appointment. Why don’t you just wait until you can have one around 9 am Jo xx

[Bookworm63 in reply to Stourie]

Think I may well ring up this morning and see if I can change it. I just got a little flustered when I arranged it. Didn’t expect it to have wait so long always got in easily before.

[Stourie in reply to Bookworm63]

The doctors who want your bloods done don’t mind waiting to see you as long as you make an appointment eventually. I’m usually about 6 weeks before I get round to it. Take care. Jo xx

[Bookworm63 in reply to Stourie]

Thank you Jo x

[McPammy]

I’d say take your liquid levothyroxine myself. Then you know 4hrs after taking it how high it gets. You don’t want to be going over the levels or have a suppressed TSH really. Aim for a TSH of about 1.00. Aim for a healthy persons level which is not over range and not a suppressed TSH and be symptom free.

I take liquid levothyroxine and find it is excellent in getting the dose right for yourself. I take 68mcg a day. You don’t need to jump 25mcg with an increase. You can pick whatever amount is good for you. 25mcg can be too much a jump % wise. You’ve increased your dose by 50%. Maybe 25% increase might be good enough. Just something to think about.

[helvella Administrator Thyroid UK in reply to McPammy]

Trouble with that is the peak of FT4 after a dose of levothyroxine (in tablet form) is typically around two hours after ingestion. With a liquid, it is almost certainly sooner.

Testing after four hours gives a result from somewhere between the peak and the trough - without much to help inform where on that slope the person is.

If you could catch the actual peak, that would show how high it gets. But that peak is a few minutes at some time after ingestion that we cannot know. (Yes, we can guess by looking at research for oral levothyroxine products. But any individual might peak earlier or later than typical.)

[McPammy in reply to helvella]

Hi I agree about the peak point and 2hrs for tablets mainly and liquid getting there potentially quicker. However , what I’m trying to get to is that it’s best not to go over the level at any point. A healthy person wouldn’t. Isnt our aim to mimic a healthy persons levels to be symptom free.

If for example you didn’t take the levo before a blood draw and the result was quite high but not over the level and the TSH suppressed. A Dr would think oh that’s ok as not over the t4 level when if you had taken your levo it will definitely go over the level which in turn over time suppresses your TSH. A suppressed TSH is never where a healthy persons levels would be. Suppressed TSH can cause symptoms when we need to be symptom free as much as possible

[Bookworm63 in reply to McPammy]

Thanks for your reply McPanmy. I have increased very slowly. As you say you can do that with the liquid Levo. I took 62.5 for about 3 months but I was still very tired and slow digestion. All my old hypo symptoms so I upped it again to 75 mcg and within about 4 weeks I felt great. I’ve been on that dose for about 3 months now and it’s beginning to level out again and some of the tiredness is returning but nowhere near as bad. I do have more energy than before. That’s why I want as accurate result as I can get. You may well be right take it at usual time and see what it is at midday might be more accurate.

[McPammy in reply to Bookworm63]

Maybe your some of your tiredness returning is slightly over medication now. Over or under medication can feel very similar. It can fluctuate over time. Try reducing ever so slightly. What I do is split my liquid levo. I take 34 mcg twice a day. My TSH is never suppressed and my t4 level never goes over either. Had my bloods done this week TSH was 1.09 ( 0.35-5.50). I also take T3 twice a day. I find it’s best splitting doses then I never spike.

[Bookworm63 in reply to McPammy]

That’s very interesting. I was beginning to wonder if I could be experiencing a bit of over dosing. It’s so hard to know with this condition. As I have read on here that we should really be prescribed by our weight I thought I may have needed another increase. If I went by my weight I could go up to nearly 100mcg. However I wouldn’t do anything like that without knowing my numbers. I’m going to start splitting my dose as you do for the next few days and see how that goes. Thanks for your input McPammy, food for thought.

[McPammy in reply to Bookworm63]

Split for about two weeks to get the best results if you can

I don’t agree with dosing by weight. If I followed that advice I’d be way over medicated. It should be worked out by your thyroid hormones TSH, T4 and T3. That’s the best way to know what’s going on in your endocrine system for thyroid levels. I aim to mirror a healthy persons levels and TSH. That’s never under or over or suppressed TSH. I am symptom free and I believe that’s down to getting my levels right for me. I take t3 also. Over or under medicated can lead to all sorts of symptoms in the short or long run I feel. I’ve been symptom free mainly now for a few years after struggling for years with grossly under medication. I go the gym 4 times a week now or take brisk walks. I’m 65 and feel much younger than I did in my 50’s when either under or over medicated due to GP’s not understanding the thyroid. I’ve since educated myself on my condition and found my sweet spot. I always now check my bloods after I take my medications to ensue no spikes. I don’t want a suppressed TSH as when mine goes suppressed I don’t feel good at all.

As you’re on liquid levothyroxine you’re in a great position to get yours right for you too.

[Bookworm63 in reply to McPammy]

Yes that is the great thing with liquid it’s very easy to adjust the dose. I’ve been taking Levo for five years now with all sorts of problems in the beginning. I thought it was down to the excipients in the tablets hence I was put on the liquid. At one point whilst I was on tablets I stopped taking it for a week because I felt so nauseous. I felt great for the first few days but by the end of the week I was extremely tired and nauseous! I realised then that nausea was one of my hypo symptoms. Looking back it may well not have been the tablets making nauseous but under medication but I’m reluctant to change back from liquid as I know it really doesn’t upset my stomach and I can feel really good on it. I have heard said on here that once on levo you are not topping up your thyroid you’re replacing it which means you should be prescribed by weight. I’ve read lots on here and have educated myself more all the time and I am open minded to all opinions. I’ve taken on board what you’ve said today and I will try the split dose to see how I get on. Thank you for replying you’ve made me re assess my options 😊

[McPammy in reply to Bookworm63]

The other thing to check if you’re feeling nauseous is your cortisol level. It must me a 9am blood check. Your gp can organise it for you. If it’s too low then they can do a synacthen test to check your adrenals are working as they should. I had nausea and thought it was my thyroid issues but it was low cortisol. It fixed when I was prescribed T3 alongside t4 levo. Just something else to consider.

[Bookworm63 in reply to McPammy]

Well that’s interesting too. I’ll bear that in mind if I have trouble with nausea again. I must admit I did look adrenal problems up at the time it happened. Your advice on how to get it checked is very helpful, thank you. I don’t know why but I always seem to feel things go a bit off course in the spring, March April time. Maybe it’s just coincidence or it’s the change in temperatures and dosing needs changing?

[McPammy in reply to Bookworm63]

I think it’s the change in seasons from winter to spring I also have some slight issues going the other way from autumn to winter. I’m convinced it’s to do with not doing as much during the winter short days. Then doing more once spring arrives. I try to keep moving in the winter months by joining a gym just treadmill or rower. Even done classes. I’m just about the finish my gym until end of October. I find that does help. I do know what you mean. And it’s the changing of the hour that each way too. We are trying to mimic what are bodies would do naturally with thyroid hormones with medication. It’ll never work as well as naturally sadly. Same goes with cortisol which is our circadian rhythm.

Hope the splitting of levo helps. I take my T4 at noon then second half at 4.30pm.

I’ve found adding T3 has been an absolute life saver. I cannot explain how good I feel these days after horrendous times I had 2018/19. I went private in the end and learned so much from my private endocrinologist. He would never dose by weight he said. And if it worked for someone it’d be coincidence rather than biological.

[Bookworm63 in reply to McPammy]

Sounds like you have a really good endo. I take on board his opinion on weight dosage. I feel you’re right about the body making its own adjustments as the seasons change and that because we’re on hormone supplement we should bear that in mind and maybe adjust our dosage accordingly. Difficult to know without constant blood checks. Think I’ll also arrange for a private test so I can see my t3 result also. Not good with blood tests lol. Will have to have it done by a nurse, too squeamish to do it myself. Glad things are going well for you now and that you’re feeling so much better. Maybe I should take a leaf out of your book and join a gym during the winter months. I do tend to go into hibernation especially in January and February! Maybe a few classes of yoga would be more my thing.

[McPammy in reply to Bookworm63]

I do think the exercise during winter does help. I get my bloods checked by my gp every 3 months without fail now. If I ever mention my private Endo’s name they all jump now.

Hope it goes well for you and you get stability back with your hormones. Low and slow changes I feel works best.