Hello, quick question to those of you on T3 only . I started T3 only earlier in the year after years of not doing well in T4. I've had a few ups and downs getting used to higher dosed but for past month or so I've been consistently on 60mcg Thybon Henning T3. Taken as 20 at 8am, 20 at 1pm and 20 at 4.30pm. I've adjusted well to this and no longer get big peaks in heart rate or temp after a dose. I love the improvements compared to T4 and for the first time in years have a clear head, clear eyesight and no muscle pain or weakness. But in the last two weeks I just feel so tired for much of the day, especially in the morning after a long gap from T3. It's not the same fall down tired I had on T4 it feels like I'm sleepy all day (it's not even unpleasant but I can't really sleep all day) . My average hear rate is also falling back to the low 60s. So my endo says that 60mcg is the absolute safe max for T3. In people's experience is that the case as I feel like I could at least try 10 more? Sorry i have no test results to share,, I've booked one for two weeks time. I'd appreciate any advice or experience people can share. Thanks
T3 only dosing how high to go?: Hello, quick... - Thyroid UK
T3 only dosing how high to go?
How high to go? As high as you need! There is no upper limit, your endo is talking rot.
Besides, it has nothing to do with the size of your dose, it's how much you absorb that cound, both in the gut and at a cellular level. And, where that is concerned, we're all different. There is no way you can have a fixed upper limit that would do for everyone. 
Thanks for the really fast reply. greygoose he’s a lovely endo but I think he’s worried he’ll get struck off if he gives me a higher dose. And as I think about it of course your right we’re all different, weight, age, sex, how much functioning thyroid we have left and all the things you mention like absorption and cellular stuff. I’ll have a word with him and see if he can persuaded otherwise my T3 only treatment feels like a good job that’s only 3/4 finished. Thanks again .
By the time you reach 60mcg T3 labs may show over range FT3...
As the dose rises TSH and FT4 fall...mine have dropped off the range.
On higher doses we monitor by signs and symptoms.....how do you feel?
Tired!
That could be a number of things but if you suspect FT3 is falling, and you know your own body best......in your shoes I might add another 5mcg. Give that 6 weeks to settle then review.
If you feel overdosed just cut back to 60mcg
Hashiboy
This must have happened to me other wise the huge doses of T3 I was taking would have most likely killed me eventually
i need 75mcg T3-only to function I have taken up to 212.5mcg ....but that signalled overmedication
You can read my thyroid journey in my bio.
My GP was not overjoyed but I've explained why I need this so I'm now left to get on with it....I suspect she now understands
i take my T3 in a single dose at bedtime....there is no single correct way to dose
On the other hand you could now be overmedicated and experiencing the converse effect of T3....you could try dropping 5mcg
Sorry if this is vague but using T3-only really is a long slow process of trial and error
You must decide!
It sounds as if you are progressing well
We'll have a look at you new labs and see how they pan out
Well done
Thanks for replying DippyDame I really appreciate all your advice. It wasn’t vague it was really helpful. I had a test on this dose about six weeks ago and T3 was nicely mid range and TSH less suppressed than when I was on T4. I don’t feel over medicated (I did briefly but this settled a while back). My waking resting heart rate is about 55bpm and it is generally about 65 to 70bpm apart from a little uptick about three hours after a dose. I feel so much better mentally in terms of mood and concentration. I have had periods of hyperthyroidism when I was first I’ll years ago and I’m not experiencing anything like that so I think I might have room to increase.
I like the idea of taking it all in one go but I imagine I’d have to transition to that slowly rather than make a sudden jump to 60 in one go.
I’m glad to be trying T3 only. Overall it’s big improvement so It’s also helpful to hear that this is going to take a while and is trial and error.
Thanks again.
Ps will definitely read your bio
You're welcome.
You say below that FT3 is mid range, that is good
You will not be overmedicated so long as FT3 remains in range so if you feel you may need an extra 5mcg you have plenty room to experiment.
As you will read in my bio the dose depends on how much of the T3 is reaching the nuclei of the cells, where it becomes active. T3 receptors take the T3 to the nuclei.
You can have a high FT3 but if the hormone is just sloshing around in the blood doing nothing, then being metabolised and excreted without reaching the cell nuclei, it will not be active and should not affect you adversely.
In that case a few, or many ,T3 receptors may have "gone to sleep", if FT3 was low for some time. Kick starting the receptors into activity again with higher doses of T3 will possibly mean you later need a lower dose. I'm baseing this on what I've read and on my own experience....I'm no expert!!
However...if the cellular level of T3 becomes too high then problems can arise....this is where keeping a close eye on signs and symptoms becomes vitally important because there are no tests to measure cellular T3 levels.
T3 may be well absorbed into the blood but it is the amount that is received into the cells that is important
Ergo.....you need what you need!!
No doubt this is why T3 freaks many out if they don't understand how this works.....but it is a potent hormone and MUST be treated with respect
Good that you have a ready source of T3.
I'm T3 ranting again....sorry!
Assuming you are fairly normal weight 60 mcg liothyronine is close to the limit above which you are on supraphysiological levels at which there are risks. ideally we would avoid this and keep the dose down a little lower. This might not be possible and so it's a matter of balancing risk against having a life.
You might try taking your doses at 8 am, 4pm and bedtime. This will even out the dose and I find I need the bedtime dose to get good sleep and avoid brainfog. If this works you could try reducing the 4pm dose, I found I was able to do this.
Liothyronine is very well absorbed so unless you are taking it with coffee, bran or a large meal there shouldn't be any absorption problems. It's more likely that this dose is suppressing your TSH and the T3 peaks are affecting how your body deals with higher fT3 levels, so evening out the dose schedule may help.
i assume you are getting your Thybon Henning from a reputable pharmacy.
Thanks jimh111 thanks for the advice. You gave me some good advice before when I was coming up to this dose and feeling over medicated, so thanks for that too. I’ll try your suggested dosing of 8,4 and bed time. I think you mentioned taking your meds in two doses Can you say how you moved to twice daily dosing? Did you shift all in one go or was it gradual. It would certainly be more convenient?
and yes I get the T3 from either Boots or Roseway
I just swapped from 20,10,20 to 25, 25 at breakfast and bedtime. It's not a big change as at 24 hours later we still have half the T3 left in our blood. The maths will get too complex but this switch will have very little effect on overall fT3 levels.
Thanks jimh111 so do you think I could do a straight switch to 30 at 8am and 30 at bed time?
Yes, but I would suggest 20 at breakfast, 30 at bedtime (or 25 /25), you might find this is enough. If you go to 30 / 30 you might find it difficult to get to sleep IF you are currently on too much (because you are perhaps not getting enough overnight at the moment). You could switch to 30 / 30 after three or four days if 20 /30 is not enough. Either way is fine.
Hi. T3 is currently still 50p per 20mcg tablet at Chemist4You. Roseway is now 60p.
Too much T3 made me very tired. Too little makes me tired. So it's a case of experiment. Knowing what I know now about me, I would say try 5mcg less first and see how you feel. Then, if that's a bust, go back to 60 for a couple of weeks and then up to 65. Although I realise that for some of us dosing is very sensitive so I'm now using a small amount of 5mcg T3 (SigmaPharma) so that I can cut them in half and get a 2.5mcg dose to move up or down by. 5mcg tablets are stupidly expensive, but it's OK to experiment with especially as I only need to use 1/2 a tablet a day to do that.
If you want to go straight up from where you are now and not try a reduction first, I'd also suggest that at your current level of medication, you might want to try what I'm doing and increase by 2.5mcg a day now. Don't want to miss perfect. You have done very well though.
I've gone from 4 doses a day to 3. I'm hoping to get to 2 at some point if I can. But I'm not worrying about that until I find the dose I feel best on.
(PS I use some T4 too now. I tried T3 only as discussed with you before, but I need some T4 in my mix it seems.)
Reading this discussion with great interest. May l ask what ratio T4 to T3 you are currently on and has it worked out for you please?
I'm using Armour Thyroid NDT, so not sure what the ratio is, but I don't add anything else at this stage.
I'm not optimal yet though. I'm still experimenting. Currently experimenting with time of dosing. I'm taking 2 & a 1/2 grains a day. That's 95mcg T4 and 22.5mcg T3.
Oh l see, your T4 is included in your Armour, l thought you meant you added T4 such as Levo, cheers 👍🏻☺️
why not just spread out your 20mcg doses ….initially at least
20mcg waking, mid afternoon and bedtime
When were vitamin D, folate, B12 and ferritin levels last tested
Thanks SlowDragon I'll switch to an 8am, 4pm, 11pm dosing pattern from today and see how it goes. I haven't had D or B12 tested ina few years so will do that (I usually supplement both). Ferritin is usually good but I might get that checked too. Thanks again for the advice.
try spacing out when you take the t3 a little more so that you take it later than 4.30 so that you’re not going without any T3 at night.
Thanks Dunkenb I really appreciate the advice. It's similar to that suggested by jimh111 and SlowDragon . As of today I've started an 8am, 4pm, 11pm schedule and will maybe then see if i can manage an evening and morning dose only. I'm in Greece at the moment so 2 hours ahead of the UK and do far have done an 8am and 4pm, and feel a bitn less tired so might be I need bigger spaces between doses of even a little drop in dose. I'll keep you posted about my experiment. Thanks once again, I think it's so kind that people like yourself take time to reply to and share your advice and experience. It really helps cos there's not really anywhere else to get this kind of help.
Hashiboy...I agree your endo is talking rubbish, your body needs what it needs! I was taking up to 250mcg T3 daily at one point. I might be an outlier perhaps but my body tolerates and even likes this this level, though I have eased back in recent times, dropping to 200mcg as I lost a fair amount of weight (approx 3 stones!) when I started seriously exercising (walking over 100 miles per month) over about 3-4 months in 2021 preparing for a long distance walk. I do though complete an independent blood check every 6 months (to monitor results) and adjust as necessary. However, I can confirm that I am still alive though...
Thanks iancpriestley good luck with those long distance walks. For the moment I'll try jimh111 's suggestion of changing dose regieme but good to know you are alive and well after experiments with high doses. The three stone weight loss sounds a little dramatic though.
I never really felt right until I bit the bullet and took it in one big dose. I think doing it this way may mean it has e ough oomph to reache all your cells whereas it might be struggling in small doses. Good luck.
mstp mstp thanks for that, I'm beginning to suspect that might be wortha go, I'm starting by takingb advice from jimh111 and SlowDragon to alter wheni take T3 as a startingn point. Think I might end up dosing once or twice a day. It does feel like making a slightly scary jump. But I was a bit freaked out when my endo suggested dropping T4 and that turned out fine l.Thanks again for posting, just wondering how was it taking your dose in one go in the beginning?
I had no ill effects at all when I first changed to one big dose rather than three small doses. I can't really recall much about it but I think I very quickly felt much better.
There's no hard evidence but it looks like single doses suppress TSH to a greater extent than multiple doses. Generally it's better to preserve TSH if you can it helps with T4 to T3 conversion and seems to have other minor functions such as a role in bone formation. Hence I would tend to suggest divided doses but of course you have to do what works.
jimh111 Yep, I've done the a divide dose today and will carry on with that too see what happens. The link below is to a paper on the effects ofa single dose of T3, and I think it agrees with you abouta sustained reduction in TSH.
europepmc.org/article/med/2...
Yes, I’ve see this study. It seems that if you knock TSH down it takes quite some time for it to recover. You can see this in figure 2 in this study, although fT3 has fallen a lot by 10 or 20 hours TSH is only beginning to recover. My guess is that with devided doses TSH won’t be pusher so low and so will remain a little higher than with single dosing. I can’t be sure of this, we need a trial of single v. multiple dosing to see what happens.
Note that in figure 1 heart rate jumps up after 50 mcg liothyronine (a high dose for healthy subjects) but then remains fairly stable declining slowly. I feel that with regular dosing we would not see short term peaks (or cardiac effects). This often suggested by endocrinologists opposed to T3 therapy but they never give any evidence. When I was on very high doses of liothyronine I monitored my overnight heart rate and although it was too high (80 bpm) it stayed steady throughout the night.
If we are on T3 the T4 to T3 conversion doesnt really matter does it?
Not if you are on high doses of T3 that suppress TSH and your fT4 is low. I feel it is desirable to have reasonable fT4 levels and a normal TSH because there is evidence TSH stimulates deiodinase (T4 to T3 conversion). This deiodinase takes place close to the cell nucleus in tissues such as the brain and skeletal muscles. This is important because it’s the T3 saturation level at the receptors in the nucleus that determines thyroid hormone activity. It’s better to have T3 generated close to the receptors rather than in the blood, especially in organs such as the brain which rely on locally derived T3.
This is an important point, T3 coming from conversion of T4 near the receptors will represent more thyroid hormone activity in the brain that supplying the same T3 level via tablets. Where the T3 is coming from matters. I’ve never seen a doctor or patient advocate make this point. I think it’s very important and entirely ignored. It helps to have a normal TSH if you can.
Hi Hashiboy, I got great advise from DippyDame on T3. I was taking mine 20 mcg 8am 20 mcg 1pm and 20 mcg 6 pm and also found I was waking feeling really tired. I also snack a lot and was very frustrated when realising I had just eaten and my 1pm dose was due! So I think I wasn't getting the benefit. I immediately switched to 30 mcg at 8am and 30mcg at 11pm. I then woke rested and awake in the morning! My hair had been falling out so I added 10mcg more in the morning and my hair is growing back. So I am taking 70mcg a day and feeling fine.
Thanks jand123 glad you are feeling better. I really appreciate this sharing your experience, as of yesterdayi switched my dosing to morning, afternoon and bedtime. If they send to help I'll make a full switch to morning and evening. So hopei get the improvement you experienced.
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