Doing Blood Tests when on NDT & T3: I have seen... - Thyroid UK

Thyroid UK

111,368 members129,502 posts

Doing Blood Tests when on NDT & T3

Clara4741
Clara4741

I have seen on the forum that you recommend doing a fasting blood test and taking NDT and T3 afterwards. I have always done this. However, what I haven't done is changed the timing of my dose the previous day as you state to do. I currently take NDT and T3 together upon waking only as I don't split the dose at present. I realise that that is a whole 24 hours prior to the blood test being taken therefore the T3 may not show up in my blood much at all. However, I don't really want to split the dose as I am worried it will totally throw everything off and that I may not sleep taking T3 the night before the Blood Test. I am not being monitored by a Doctor as I am doing everything myself so wondered what you would advise I do to get around this issue? Is it okay to carry on as I have been doing? I am really unsure how best to proceed and am aware that Blood Tests are not the be all and end all anyway, particularly when you are on any type of T3, hence I am taking more note of my signs and symptoms which I monitor daily. Many thanks in advance.

24 Replies
oldestnewest

As long as you realise that you will always have a false low FT3, if there aren't any doctors involved, it doesn't really matter. Besides, it's how you feel that is most important. Personally, I self-treat with T3 only, and I never even bother to do tests - haven't had one since 2014. I know how I feel, and that's good enough for me. :)

Clara4741
Clara4741 in reply to greygoose

Yes I agree, I am not checking as often as before but as I periodically recheck my Vitamin D, B12, Folate, Iron etc. to ensure I remain optimal I just wanted to see how things are shifting adding in the additional T3 i.e. TSH getting more suppressed etc. I listened to an American Thyroid Expert recently who said she gets her clients to do their Blood Tests 2-3 hours after taking their NDT and T3 Meds, as it gives her the result when the T3 is at its peak. Apparently it really helps her with their dosing and they never overshoot then and go hyper. I liked the sound of this as it seemed to get around the issue I mentioned about not wanting to split my dose 8-12 hours beforehand, so I did it like this last time but my T3 result was ridiculous, it came in at FT3 18.9 on Medichecks range of 3.1-6.8. Previously I had been FT3 3.0 on the fasting test when I hadn't taken anything for 24 hours and took the meds after the blood test. Do you take your T3 all in one dose or split it? I know this is the way people are generally advised to do it but I wondered on your view of taking it all in one go first thing on waking - if the person can tolerate it, that is? That is what I have been doing so far as I am currently doing a very complex Quicksilver Heavy Metals and Toxins Detox Protocol (3 months) which would make it hard to mult-dose T3 too at this point in time. Plus I haven't felt the need to as yet but I don't want to go too high on one single dose if that isn't advisable. Currently no cortisol issues and adrenals are pretty good albeit still balancing further. Many thanks in advance.

greygoose
greygoose in reply to Clara4741

I listened to an American Thyroid Expert recently who said she gets her clients to do their Blood Tests 2-3 hours after taking their NDT and T3 Meds, as it gives her the result when the T3 is at its peak. Apparently it really helps her with their dosing and they never overshoot then and go hyper.

That sounds like BS to me. For a start, if they're hypo, they cannot go hyper, the thyroid doesn't work like that. And, maybe they never overshoot - although I don't know what's so terrible about that - but are they actually getting enough T3. I'd need to talk to her patients before approving of her methods. Frankly, the doctor is the last person to be capable of judging a patient's progress.

I take all my T3 in one go. Doesn't have any effect on me. But, then, I think I'm a pretty insensitive creature. I could take a lot more than I do without it having any adverse effect. And, I don't detect much difference between the different brands - they all seem the same to me. So, maybe I'm not the best person to ask. :)

Clara4741
Clara4741 in reply to greygoose

GreyGoose you sound like me! I have so far got up to Metavive 60mg (approx. 8mg T3 + plus any I convert naturally) and 62.50mg T3 and felt fine. But Paul Robinson says in his book only a few people can tolerate and he prefers it to be split into at least 2 doses depending on the individual. I was worried I was going to high in one dose albeit the average dose seems to be 40-70mg for T3 for most people with some needing far more up to 175mg! How much do you take? After my result I went back down a bit as I was worried how to proceed not knowing how much to interpret the blood test result as valid. Any further advice would be greatly appreciated.

greygoose
greygoose in reply to Clara4741

I take 75 mcg right now. But I have taken as much as 225 mcg in one go - and know of others on similar doses.

I don't think Paul Robinson's ideas would suit me at all. He writes for a certain type of person - like himself - but I don't think I fit into that category. We're all different, and have to respect our own needs. And, it's all very well for those that aren't even hypo to hypothesis about average doses, but, you need what you need if you want to be well.

Clara4741
Clara4741 in reply to greygoose

I totally agree. Thank you Grey Goose, you have put my mind at ease now as I thought I was proceeding well with my plan as I had been feeling fine on the dose I was on, it was just the Blood Test Result that threw me. Stop the Thyroid Madness Janie Bowthorpe also has an article on T3 Pooling on her website which I read and so that made me cautious too, even though everything I have read about taking T3 says that some people need much higher doses and that if you have cellular resistance (which I have, plus DIO2 Gene SNP) that the only way to bypass this is by flooding the cells with a higher dose - i.e. what I was intending to continue doing. I have deliberately kept the Metavive at 60mg as I don't convert well and went Thyrotoxic when I approached nearly 180mg and even then my numbers were not optimal. So I have been dosing heavier on the T3 as I titrate cautiously every 5-10 days depending on how I am feeling. My issue now is in getting enough T3 from a reliable source as I do not get it via NHS or Private Prescription. Obviously the latter is an option but not sustainable long term especially if I am on high doses. Urgently need to find reliable source so I can get my life back.

Clara4741
Clara4741 in reply to Clara4741

Meant to add that Paul Robinson doesn't believe in T3 Pooling anyway! Read a whole article that he wrote on it. I am not someone who dips after the T3 wearing off so have stuck to single dose as it is also easier around all the other supplements I take. :)

greygoose
greygoose in reply to Clara4741

I don't believe in T3 pooling, either. T3 half-life in the blood is 24 hours - and that's what doesn't get into the cells, and obviously some does get into the cells, or you'd be dead - so how does it have the time to 'pool'? I don't like STTM, I think it gives a lot of false information and is far too dogmatic in its approach.

I don't dip, either. But, then, T3 doesn't 'wear off' - another strange idea, like it was an aspirin, or something. As I said, the half-life of T3 is 24 hours in the blood, but what gets into the cells stays there for about 3 days. And, during that time, you are topping it up every 24 hours, so how can it 'wear off'? It can't. Unless, it's all getting into the cells, and there's none left in the blood - hardly likely - but then again, if it's in the cells, that's were it does it's job, doesn't matter what's in the blood, because it doesn't do anything there. So, all in all, the idea of it 'wearing off' is just another myth that puts doctors off prescribing it.

Clara4741
Clara4741 in reply to greygoose

Indeed, I agree with your view point. Really appreciate your advice GreyGoose. I tend to be someone who just tries to figure everything out for myself and rarely ask for help. You have reaffirmed that I should trust my instincts and judgement as they are good (and always based on thorough research anyway) but that reaching out to others on a forum like this is very worthwhile too and can give much peace of mind. Many thanks again. :)

greygoose
greygoose in reply to Clara4741

You're very welcome. :)

SewinMin
SewinMin in reply to greygoose

I take NDT, not T3 (at present), but can't say I've noticed it wearing off. (Though my dose is larger now so I do dose twice but that's more because I don't want to have too high a T3 peak if I can avoid it - I figure it is going to be two smaller peaks this way.)

It would take several days to "wear off" or be completely gone. As far as I know, the half life means that after 24 hours, half of it is still there, and after another 24 hours, half of the half and so on, but by then you've taken another two doses, one of which has worked it's way to half so it all adds up. So it would take several days of not taking it at all to be all gone.

greygoose
greygoose in reply to SewinMin

Sorry, are you replying to me, or to Clara? :) You're more or less repeating what I just said.

SewinMin
SewinMin in reply to greygoose

Yes I agree with you.

greygoose
greygoose in reply to SewinMin

OK :)

Clara4741
Clara4741 in reply to SewinMin

Just out of interest how much NDT do you take?

SewinMin
SewinMin in reply to Clara4741

3 grains but I'm due a blood test soon. Hopefully no change. A bit more in the am and a bit less in the pm or later in the morning.

Hidden
Hidden

I do this as well. I've read that you should estimate that your FT3 levels were about 25% higher on the previous day and take that into account when adjusting the dose.

SewinMin
SewinMin in reply to Hidden

Good to know.

SewinMin
SewinMin in reply to Hidden

Do you know how that varies over time? If I do blood test at about 24 hour after, I add 25% to my FT3, do you know what it would be at, say, 18 hours?

Adding 25% to my last FT3 takes me into the top bit of the T3 range, but it wasn't 24 hours, it was more like 17 hours, since it was done first thing, but my pattern of taking the meds then was first thing for the first dose, and about 3pm for the second. I was standing in queue before pathology opened so I could get in first! Now my pattern is to take first thing (5:30am lately, which is really annoying), then second dose a few hours later at say 10 or 11. I'd prefer the second one later, but my schedule is so erratic that 10/11am is the best/most consistent time I can do it.

Hidden
Hidden in reply to SewinMin

No, sorry, I don't know - the 25% is a rough estimate given the alleged rate at which T3 decreases in the body (half-life).

Over the years, I have come to worry less and less about slightly elevated FT3 levels. Often, I see advice like "it does not matter if your TSH is suppressed as long as your FT3 levels remain in range". At the same time, it's often said that FT4 levels can be slightly elevated in people on T4 only drugs. So, I'm wondering, can anyone prove beyond a reasonable doubt that slightly out-of-range FT4 levels are harmless, whereas slightly out-of-range FT3 levels are dangerous...? Somehow, that does not sound very logic to me.

Looking back - and I've lived with Hashimoto's for over 20 years - I realise one thing: whenever my FTs were slightly over range, that never, ever caused any side effects. The only time my FTs have really told me something was when I was UNDERmedicated, meaning they were in range but not optimal. Apart from that, they have not been much help so I go by symptom-relief only. But that's just me.

SewinMin
SewinMin in reply to Hidden

I guess it's that the T4 is thought to be a prohormone and the T3 is the active hormone? Mine has never tested as anywhere near the top, except when I add on the 25%. But it wasn't 24 hours since the test, more like 17, so 25% is probably too much.

In a way I'm reluctant to mess with my meds for the test because as it is I'm getting a consistent snapshot of my dose in the morning, before I take my meds and my second dose has been varied over the years (absent, small, larger, earlier, later). I was surprised at how little an increased bit of T3 (messing with my meds gave me another 5 or 5 mcg of T3) made to my blood test result.

My TSH is suppressed (or at least it was and I can see no reason for it to not be this time around, lol). While I'm not overly concerned about that - I haven't seen anything conclusive that shows that the low TSH in itself is an issue, however, this indicates that maybe the TSH does have actions outside of the thyroid (but I can't get the whole document, or rather I'm too cheap to buy it): sciencedirect.com/science/a... . So, I guess the jury is still out for me on that one - why are there receptors if nothing is being done.

I also saw something that suggested that TSH was necessary for conversion of T4 to T3. Not much of an issue to me as I take NDT which has a higher T3 to T4 ratio so I'm not so reliant on conversion, and frankly I'm not convinced I was doing it well even when I did have a measurable TSH!

I take my NDT in two doses to minimise the peak of T3 in the blood, though I'm not sure how important it is. I read something (Tired Thyroid?) that suggested that the peak of T3 might make the body go "OMG, too much T3: make RT3 instead", and I don't want that! I know there's a bit of controversy about RT3, but when mine was way high, I felt awful - cause or effect, who knows.

I also am prepared to take my chances with my bones from a point of view of low TSH - I have to get through life, after all, and I might not even get to old age. I'm not so comfortable with a high FT3 though and would prefer to keep it in range, especially now that I'm feeling okay.

Argh, again I've written a novella. Sorry!

I don't do the game playing of Levo requires one gap, and T3 requires a different gap either. I take both my T4 and T3 together at night, and don't do the 12 hr thing with T3, partly because faffing about with different dosing is not how I want to manage my health and life, but also because with NHS testing my aim is to avoid inappropriate dose reductions which happen all too often as it is; so if my level is fractionally lower than it would be had I left only a 12 hr gap, that's fine, it doesn't make any material difference as long as I'm not feeling remotely over-medicated - and I've never yet had a GP gasp in horror at how low my level is, and offer a dose increase; but they certainly jump to a dose reduction all too readily ..... And truly, Drs will happily have blood drawn at any time of the day, and don't concern themselves with if the patient has eaten, or when and how much, or if they have or haven't taken their meds, or when, yet nevertheless make dosing decisions based on the results, so it's all very much hit and miss in any case. I think consistency in the conditions for successive blood draws is more important than messing around with splitting or shifting dosing.

I realise that that is a whole 24 hours prior to the blood test being taken therefore the T3 may not show up in my blood much at all.

Well in my case I know it does, because when I leave a c24 hr gap along with my T4, my FT3 is about 5.6, and when I was without T3, my FT3 was 3.2 - so it is definitely visible, 24 hr gap or not.

Clara4741
Clara4741 in reply to MaisieGray

That is good to know and I like your thinking! I kind of felt that if I continued to do what I had always done regarding the testing that it would still show an increment in the Free T3 over time as I cranked up the dose - assuming it was getting in. This seems to be what you are saying too. I am also bearing in mind the fact that FT3 levels are less reliable on blood tests anyway, particularly when you start taking a Thyroid Medication containing T3. Plus it is likely to suppress the TSH and also potentially lower FT4 results. I think I will continue to do what I am doing i.e. 24 hours after previous dose (all taken in one-go and fasting around 9:15/9:30am - taking meds after) as that is what suits me best and as you say that is important - fitting it into your lifestyle. Thanks Maisie Gray you have been really helpful. Now I just need to get a reliable source of T3! :( Just out of interest, did you take your temperature and pulse daily when trying to optimise your dose? That is what I am doing and have done all along. Apparently this is a much better way of telling how well the T3 is getting into your cells as well as monitoring your signs and symptoms.

MaisieGray
MaisieGray in reply to Clara4741

No I don't, TBH. My pulse is measured by my Omron along with my BP, when ever I check that (I have hypertension so test sporadically at home, and also have a cardiac problem) but I don't formally monitor my pulse for dosing purposes. I did have a spell of temperature-taking, and if memory serves, I was variously achieving numbers in the 35's and 36's, it wasn't fixed (I can't check as my lap top with the data died the other day). However, when I presented them to my GP as possible evidence of something or other, he glanced at them and said "I'm not concerned with those" ..... So I gave up checking. However, I don't think you can take a lower temp as necessarily always proof of under-medication because more recent studies have shown that there is a much wider variation in healthy individual temps than has previously been said; and so the more important issue is whether one's temp is consistently lower since developing hypothyroidism, than when euthyroid, rather than simply what it is now without knowing what it used to be - and how many healthy people routinely take their temperature? ie we shouldn't strive to push up our temp by increasing T3 to a level that is the alleged "correct" temp, if that isn't "our" correct temp. However, all that said, I don't subscribe to the fine tuning and attaining of "the sweet spot" that others strive for - for me, my hypothyroidism and meds are just a small part of my life, not its focus.

You may also like...