The time gap of 24 hours was correct for Levo but for T3 you should have split your dose the day before the test into 2 or 3 and should have taken tbe last part 8-12 hours before the test. By leaving 24 hours you have a false low FT3 result .
How do you feel ?
I take Levo plus T3 and take them once a day except when testing and then I split my T3 into 2 doses the day before.
The 20% is a guesstimate, there's no way of knowing it's accurate for an individual unless they've tested with the advised time gap and compared results.
The 20% ia a 'guessimate' based upon what was available then and if you read older posts on this forum you will see that was the suggested. However, the available calculation has since been abandoned as there are too many variables.
Why is it a false low? If somebody doses only once a day then their ft3 will really be that low every day at that time under normal circumstances. What has been measured is the lowest that the ft3 gets on a once daily dose.
As evidenced by the replies here, there is so much debate about the best time to test for an ‘accurate’ reflection. Taking bloods is just one of many ways to evaluate if you need a dose increase and helps provide different pieces of the puzzle. What is your temperature like? What are your current symptoms? What is your HR like?
I would not adjust my dosage based simply on the bloods, you could have excellent bloods and still feel poorly. I think the over reliance on bloods these days is detrimental to getting well in many cases. There are too many variables and once you add T3, getting an accurate reflection of what is going on at a cellular level is even trickier.
Have you had your Vitamin B 12 , Folates , Vitamin D and Iron/Ferritin tested in the last six months ?Yes, these could be age , but also low B12 or Folates , or Vitamin B 12 or Folate deficiency are often more common in older people but seldom regularly tested for.
These issues can effect your thyroid function and how well you absorb your thyroid medication, other drugs , supplements and nutrients from food too .
They cause a lot of issues in themselves including Fatigue , Insomnia , Palpitations, Dizziness , Muscle weakness and problems with digestion , skin and hair.
It's worth requesting for these blood tests to be done as regularly as you are allowed , especially if you have thyroid issues , and collect the results just as you do for your thyroid panel , as if they are borderline low they will tell you it's normal , but what is normal in the range may not be normal for you and you may need to start B12 and Folate supplements, and extra Vitamin D to prevent them getting worse or to improve your overall symptoms.
If total B 12 results keep showing as normal but your symptoms are not improving you need to request an Active B12 test to make sure that proper B12 conversion is occurring.
I had very rapid weight gain in strange places , the muscles were weak and reducing in size on my arms and legs and my skin and hair were awful.
I had both Vitamin B12 deficiency anaemia and Vitamin D deficiency. Since starting injections for B 12 , and increasing folate and vitamin D supplements I've been able to control my symptoms better. I think it's worth ruling out anything else going on before changing the dose just in case there is a missing piece in the jigsaw that a thyroid drug modification alone won't change as much. Hope that is useful. Take care , Bee
yes I have all of these tested every 12 weeks by my haematologist. They are all optimal and I’m very careful to keep them that way . Have done this since 2014
That makes sense that it’s the lowest it will be if taken once a day. So theoretically it’s actually higher through the day than the results show? Perhaps that’s why I don’t feel the need to dose throughout the day!
Do you think the results are ok? Only asking as I have put weight on over last couple of years and my constipation is quite bad so need to take a laxative at night
Yes both ft4 and ft3 are at their lowest. So for most of the day your levels are higher. If you tested 2 to 4 hours after your doses then you would get ft4 and ft3 around their highest.
If you tested ft4 and ft3 around 12 hours after doses you'd get an average level .
If those were my results and I wanted to see if I could improve lingering symptoms I might consider testing after 12 hours to get an idea of average levels to see what leeway I had to change doses.
Or based on the lowest results I might consider reducing my levo slightly by 12.5 per day maybe and once levels had dropped, adding in another 5mcg t3. This would be to see if that different balance between t4 and t3 improved the lingering symptoms.
On combo it is trial and error as to the doses we need. When we are reasonably well we don't want to make big changes to spoil what we already have.
I would also add that after 18months on steady levo t3 doses I am still finding that symptoms are improving with no changes to my dose so it can be a very long term thing
"I can’t test 12 hrs after taking my morning doses as that would be 8pm and Drs are closed then."
8 -12 hrs is good enough for T3 , it doesn't have to be 12hrs .
(8 -12hrs is far enough away from the dose of T3/ T4 to miss the 'high peak' that happens when it is all absorbed into the blood all at once .. this high peak lasts from aprox 2 hrs after taking T4/T3 ~ to aprox 4-6hrs after taking them) .
So eg. you could take T3 at 7 /8am and test at 3 /4pm . This would show your mid/ average levels for that T3 dose pretty well ... however it's important to note that it would not show TSH at it's highest.. in late afternoon TSH would still be pretty close to it's lowest ... TSH is lowest between aprox 1-3pm each day ,then rises again to it's highest around midnight-2 am (aprox).
If the results are going to be seen by a GP you really don't want' to be showing a GP a lower TSH .. or else it is highly likely they will want to reduce your dose.... however in your case your TSH is already lower than they can measure.. their test machine can't measure anything less than 0.03 (hence the <) .. so if they are OK prescribing with your supressed TSH , it may not matter in this instance .
If results are 'just for you' , and you're not interested in getting the highest TSH, you can test at whatever time of day you want ... eg. you could get a private fingerprick test and test at 8 pm if you prefer.
Note ~ if you test Levo after 8 -12 hrs and you usually test after 24 , the result you get for fT4 will be slightly higher than you would usually get... but 8-12 hrs is still long enough to miss the high peak that happens between aprox 2-6 hrs after taking Levo .
These graphs show the effect of fT4 / fT3 levels at various time post dose .
Top Graph ~ Top Line shows fT3 level. (in people taking T3 + Levo)
Middle graph ~ Bottom Line shows fT4 level (in people taking T3 + Levo)
What time the FT3 level is high in the blood is not an indication of what time it get's into your cells... it doesn't do anything in the blood .. it just goes round .. it only 'does something' once it gets inside a cell , once inside a cell, it makes that cell do 'whatever that cell does'.. (heart, brain etc )... the 'action' of T3 on that cell can last anything up to about 2 or even 3 days,( depending on all sorts of complexities)
So you can't look a those graphs as showing 'when you feel it '... they simply show when the level s are highest/ lowest as they are being carried around in the blood .
As for fingerprick vs venous ?.... it is not so much that which makes for all the variability we see in FT4 / fT3/TSH testing (although it may obviously have some impact .,,and some unforseen cock up's resulting in failed tests eg delay in sample arriving at the lab due to sitting in a hot post box during a strike in june etc.. or damaging the blood cells as they come out by squeezing the finger etc etc )
there are just as many differences in NHS venous tests when the samples are tested at different NHS labs , due to them all using different test platforms( machine) which use diff anaysis methods , made by diff manufacturers , and having diff [ref ranges] . The whole fT4 / fT3 / TSH system has a large ( and unacceptable) level of variation in results , but it's the best we've got at the moment (until the endocrinology profession pull their finger out and demand better/ closer comparability between diff test platforms/ labs ) .
So to get the best possible comparison between our own tests, we not only need to keep the variables of 'time of last dose' and 'time of day' under control ... we also need to use the same lab as far as possible.
I’ve been doing private finger prick tests on same day as NHS tests for a while. The ranges are different so they’re never the same result, but there’s a lot of similarity. Eg. If T3 is above range on one it usually is on the other.
Yes I agree with you Lala- it makes logical sense that if the take your dose at the same time once per day in the morning then the blood draw the following morning- if done consistently around the same time- will yield a consistent result of it being at lowest.
I take my NDT at 5.30 am and 11 am and don’t adjust It the day before a test. I consistently do/have tests done at 9 am which is 22 hrs after I take the second dose. I have no problems doing it this way. For me my blood work is a guide not gospel- and my dose in accordance with the alleviation of symptoms..
Don't worry. You just need to be logical and methodical and think about what you want to try. On combo it is all trial and error to see what suits.You can keep things as they are with your lowest ft4 at 78% and your lowest ft3 at 61%.
You could test at 4pm as tatty suggests to try to get more of an average idea of levels to see if that helps guide you
You could alter your current doses based on the results we have been discussing. As you don't want your lowest levels any higher I would suggest that your first step would be a reduction in levo dose. Wait 8 weeks then do bloods. See what your levels are and how you are symptom wise and decide what to do next.
It is not easy to decide what to do. It took me 2 years of slow methodical dose changes 1 thing at a time and then waiting 8 weeks and doing blood tests, till I found doses I wanted to stay on longer term.
I measure ft4 at its lowest and ft3 at its average level. My ft4 low is 50% and my ft3 average is 72%.
I’m going to need to do this soon but am on a tiny 5mcg dose of T3 and it’s a capsule. I already split T4 50 at night 75 morning.
Should I empty the capsule out and cut it with a credit card like a drug dealer….? Create myself 2 ‘lines’. 🤣 ( you can tell I’ve been thinking this through) I need the results to show low really, I have felt fab on it and it’s really settling nicely so I don’t want to change down or up.
Regenallotment I’m really happy to read you’re on T3. I remember you posting about long term depression/anxiety and suspecting a low T3 to be involved there. May I ask how you’re doing on it? X
So from my point of view, my question is to do with your post, I share your experience and take my meds similarly to you, I have the same question. So by contributing and adding to the responses, I have helped push your message up the reading list of the forum, enabling you to get more responses, I find reading other’s responses helps us all learn. I apologise you feel this post is hijacked and will be careful in my responses in future.
Socialite or gangsters moll hmmm 🤔 or watching too many dodgy movies 😏
If you want it to read low then leave a good gap and split the capsule, you can just mix half with water... though snorting might be hilarious so be sure to film it for us 🤣
Plenty of air in the capsules and see through so quite easy to judge your split and put the cap back together 🤗
You can never have too low a reading for an Endo 🙄
There is a complication if you take combination T4/T3 like NDT. If you do the test 24 hours ahead the T3 will be low, but if you do 12 hours ahead the T4 will be high and TSH too low. I tend to opt for 24 hours and acknowledge the T3 will be low, mainly so the GP doesn’t panic and I don’t have to get into a huge debate with them about why I don’t need to reduce my dose based on artificially high T4 and low TSH (if that makes sense…….)
And fT4 is 'not much affected' by the time you get past 8-12 hrs... it is most affected between 2-6hrs post dose .
See the graphs i posted in other reply on this post Buttercups ~they are showing levels on T3+Levo combo rather than NDT , so not direct comparison, but .. TSH is not affected by time of last dose because that level has already been set by the levels of T4/T3 during the previous few days /weeks . TSH doesn't change on a day to day basis as a result of time of dose , but it does change each day as a result of 'time of test' due to the circadian rhythm for TSH . higher middle of night ~ lowest mid afternoon
my TSH has been slightly suppressed. My T4 low (just now scrapped into bottom of range, was below) and my T3 is low. Hence why I don’t want to risk arguments about lowering dose as I have already had comments about needing to lower dose to get TSH in range, even with a T4 of 9 (reference range 12-22!!)
interesting. There are people on here much more experienced than me, but I’m wondering if you take them separately whether the best timings to test are 12 hours after T3 and 24 hours after T4. I wonder if that might raise your TSH and lower your T4……
As I say I’m not an expert and am only speculating if it would give a different perspective of your levels…..
when I’ve put my results here before after leaving a gap of 24hrs I was asked to test t3 after 12 hrs which is why these results are like this as the purpose was to see what T3 was like.
After 24hrs my ft4 is always around 14.1
5/9/22 150 Levo plus 15mcgs T3 last dose 8.20 previous day TSH <0.03 (0.35-4.94)Ft4 14.1 (9-19) 51%Ft3 4.3(2.6-5.7) 54.94%Add 20% = 5.16 82.58%100 Estradot patch 24211/11/22150 Levo 15mcgs T3Last dose 24hrs previous day Tsh <0.03 (0.35-4.94)Ft4 14.1 (9-19) 51%Ft3 4.3 (2.6-5.7) 54.94.%
If you want to know for your own benefit you could do a home test 4hours after your morning dose and it would give you your highest levels which might be good to know? It's likely that your T3 is going to be quite a bit over range
It should give you a much better idea how your body deals with the one dose as you now know where you are after 24 hours.... I assume us one shot wonders naturally take longer to absorb as we don't feel a spike? If you are feeling well on your current dose I wouldn't rock the boat 🤗
The range is intended to cover all the ups and downs of cycling T3/T4 one would assume?
Ah sorry I thought you said you weren't under a doctor so using private testing, so could do an evening test and pop it in the fridge till posting the next day?
Some GP's do later sessions maybe worth an enquiry?
Completely empathise. Just to comment I take mine once per day in the morning first thing. Ive been told the same by this forum re testing of ft 3 and ft 4. Sadly I'm on a ndt so it's just not possible without messing around with the ft4 result and my normal dosing regime. What do I do then.....well I stick to the 24hrs rule gap as that's what my endos who are ndt friendly have told me over the years! And in addition I check Temp/ pulse first thing before rising & look at signs & symptoms. Paul Robinsom has never found on his T3 only regime that dosing via the T3 result only to be very reliable. He & his GP found that if they were guided by Ft3 levels only they were constantly changing his up & down & he didnt feel well. This is because T3 in the body is naturally so variable and subject to a wide variety of factors unlike the ft4 level, which changes very slowly over a much longer period like weeks. Eg cold weather, level of activity, intensity of activity, food etc So you'd have to control all your environmental, personal, activity and emotional, stress levels as well
...as Ft3 level will be affected by all of these. Inaddition Ft3 has a natural cycle of level of Ft3 - ut naturally goes up and down in people who are not medicated, unlike ft4 which is far more stable Most of us who use a combination treatment do convert but not sufficient so a top up of some ft3 helps and who knows may aid better conversion..no one really knows. Precisely what you & I are doing with our meds
I'm inclined to agree with Paul Roninson re testing ft3. ....
At the end of the day it comes down to how you feel and whether you have any signs of over or under dosing......ultimately. I know forum members on here don't agree with me and therefore dont agree with Dr Skinner, Dr Peatfield and a well regarded nhs endo that I wont name as he still practises who ALL advised me on a 24hr gap before tresting. So until science moves on with it's rather crude blood tests I'm sticking with their advice.
I'm NOT saying however what you should do however.....just commenting on what I do and why & what I've been advised by professionals.
Great advice, presumably you are well within range after 24 hours even on NDT though it isn't really comparable with it giving a slower release of T3 ?
The thing is to understand the limitations of testing and just aim for continuity in your personal choice of regime whether it be 2-4 after, 8-12 or 24 hours and try to understand your own cycle.
I don't know about NDT but the advice on here seems to lean toward symptomatic monitoring rather than blood testing as it is a very different method from the separate pills and has other limitations 🤷♀️
Hi Eeyore......didn't know ndt gives a slower release of T3 than synthectic, thats really interesting.....can you tell me more? Maybe pm me or a separate post as per the posters request. Thanks 😊
It is thought that because NDT hormones are bound to thyroglobulin they are not available until digested. Hence why some say HRT offers a smoother ride.
🤣 Yes I defo found/find ndt gave/gives me a much smoother consistent ride....no ups or downs just level....like before I developed hypothyroidism. Hadn't thought if it is slow release.....interesting idea.
As your thread has stimulated discussions with others who are interested, as the original poster you receive all questions and answers though they aren't necessarily aimed directly at you 🤗
We all learn so much from this criss cross of information, sorry it can be a bit bewildering when your thread is popular
130396, This is a public forum, which means that anyone can comment on anything. We know it's frustrating to get replies that are not directly in answer to you, but this is the way of things on public discussions. As TiggerMe says, everyone can learn from things posted here.
If you don't want any more replies at all to your post, you can ask an admin to close it for you.
Whenever you get a group of people in the same room, discussions almost always go off topic. This forum is no different. It's human nature. You can ignore replies that aren't relevant to your question.
I've got to say if you meant synthetics only then it's best to say so. Might have been better to say those on levothyroxine & liothyronine. Then I wouldn't have responded because I would've known. Hope you get sorted.
waveylines, The problem with the word 'synthetics' is that people instinctively think of it negatively. Unlike 'natural desiccated thyroid' which is considered to be good because it is natural. The fact that both are highly processed in factories seems to escape people. There's probably very little that's 'natural' about desiccated thyroid by the time it's become pills in a pot on the pharmacy shelf.
Redapple whilst I acknowledge what you say to a point in the sense that all ndts have to meet the same variance of active ingredients as other drug/hormone requirement the Endocrine Website refers to ndt as 'natural' & liothyronine as 'synthectic.' endocrineweb.com/conditions...
And since we have been asked to discuss only levothyroxine & liothyromone maybe we might need a new thread to discuss this?
Have you been on the wine, you're all over the place with your words 😆? Perhaps we just need to agree that they all have excipients that need to be looked at perhaps more closely than the active ingredients...🤔
🤣😂😄 what me? Nooo never your honour! Sober as a judge.... (hic)
So if ndt T3 is slower to be taken up and slower to reach half life, doesn't that also mean the protocol for Liothyronine testing recommended on here would not work in the same way for ndt....due to the factors above. So that might be why my lovely clever docs just test 24hrs after not taking ndt as per levothyroxine? Makes sense!!
It's not really clear cut as splitting doses can increase absorption for some so there really are no hard and fast rules... I tend to split my dose for the benefit of the NHS (as they need to be the lowest so as not to risk a cut in prescription) leaving the 8 hour gap and for my own tests I don't to see where I peak as I test within 4 hours of last dose to give me a good overview.
So it is timing and dose/ splitting that effects the outcome and also the variables of different metabolisms etc....
Hi there 🙂I've been taking T3 and T4 once a day for 20+ years. I take 20mcg Liothyronine with 50mcg Thyroxine (I had it reduced from 75mcg last year and feel so much better for it). I also take Sertraline 50mg and swallow all three pills together whenever I remember - usually before noon. I've only had questionable results once, which is when my T4 was reduced from 75mcg to 50mcg. Hope this is useful. x
Hello again! I'm quite lax with my blood tests. I should have had my last one done about 4 months ago, but because I'm feeling so well I've been procrastinating. GP send me reminders so I might pop along to the phleb clinic tomorrow while it's fresh in my mind. I started on the lower dose in August last year because the GP said my T4 was "modestly over-replaced" and we need to avoid suppression of TSH. My Serum TSH level was 0.05 mu/L which is below the low reference limit. He had suggested I come off the Liothyronine (imagine my reaction to this sanity saver!), so he then opted to reduce the thyroxine instead. It certainly has given me a whole new look at life, although I have to admit to feeling cold as opposed to the unnerving hot flushes every day. x
thank you for your reply. Do you know what your results were before you reduced your dose? Abd do you know how big the gap is from coding to blood test?
I take 100mcg levothyroxine and 25mcg liothyronine as a one off dose early in the morning with water nothing else for an hour. I have twice in the last 3 years taken 2 blood tests three days apart, the first splitting my dose of liothyronine as suggested and then blood test approx 12 hours post t3 and 24 post t4. I then 48 hours later repeated the blood test 24 hours after taking both drugs. On the first occasion the ft3 was 16% higher on the first blood test from the second and on the second time of dual blood tests ft3 was 18% higher on the first blood test. I haven’t found any difference in how I feel if I split the dose of liothyronine so I continue to take both together which seems to work for me.
I don’t plan to routinely take 2 blood tests but it was curiosity to see the difference. I now plan just to test privately once a year six months after my ‘yearly’ nhs blood test. I would of course check bloods if I felt less well.
Looking at your results your ft3 is approx 62% of the range which is quite high for 24 hours post dose. If however you feel well with no adverse effects I would be happy. Ft4 is in range and TSH only slightly suppressed. As I’m sure others have said blood tests are only a small part of the jigsaw. It is definitely worth checking vitamins as well and supplementing if necessary.
Please remember we are not health professionals only fellow hypothyroid sufferers. Normal signs of over replacement with liothyronine would normally include some or all of the following, raised pulse rate, feelings of restlessness and or anxiety, loose stool. It may be that whatever is happening to you may not be connected to your thyroid replacement hormones. If you have had a change in bowel habits I would urge you to talk to your gp. Good luck.
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