T3 Dose Increase; How do I know when to increas... - Thyroid UK

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T3 Dose Increase; How do I know when to increase? And then when to stop?



I have ME/ CFS, Fibromyalgia and am hypothyroid. You've all be wonderfully helpful in deciphering my blood tests and getting me onto T3. I've felt so much better these last few months!

However, in this past week I've been struggling. I'm still taking my supplements, but my nails are flaking again and I just feel wiped out. My pain has also increased.

That said, compared to the beginning of the summer I'm a different, far healthier person (it's all relative!) but I'm fairly sure I need to raise my dose again. I just...hurt all over as before, feel mentally sloppier, and the other T3 benefits seem to have slipped down a gear or so too since their original improvements.

I was on 75mcg Levothryoxine (according to you guys I was being underdosed on this anyway), and as you recommended I am continuing with that and adding T3.

I have worked up to 6.25mcg of T3 (1/4 Tiromel) three times daily. My last increase was 2 weeks ago. Is it too soon to add in another fourth quarter poll dose during the day? Or am I going about it wrong?

I know what accidentally going hypERthyroid feels like and I'm not there yet.

I would love to have blood test results to show you, but unfortunately I'm too broke this month - Vitamin and mineral supplements cost a fortune!

So, in the absence of hard science, is it possible to judge my T3 dosage by feel, until I have the money to get my bloods done?

And if so, do I (theoretically) just keep adding a quarter Tiromel into my day every few weeks until I find my T3 'sweet spot' (and eventually find the cash for another ream of blood tests)? Please offer instructions!

Many thanks for your help on this matter,


24 Replies

I do not split doses of T3 (you take a very small dose). The reason being that (some have false ideas about it) T3 has to saturate our receptor cells and then the work of that one dose lasts between one to three days. It is the Active hormone. T4 is inactive and has to convert to T3. I have read that those who have fibromyalgia etc usually have a resistance to thyroid hormones and that T3 only may resolve their pain/symptoms.

If we took too much of any thyroid hormones we'd have clear signs, i.e. too hot, sweating, heart too fast etc.




Thyroid hormones have to be taken on an empty stomach, with one glass of water and wait about an hour before eating. Food interferes with the uptake of the hormones.

We can adjust up/down slightly till we find a therapeutic dose.

I am not medically qualified but am now on T3 only and have no clinical symptoms.

Abi-Abster in reply to shaws

Thank you Shaws for your reply. I'm aware of much of the above, except for the 'split doses' part, as that's what I was originally recommended to do on here, and is a method many people seem to follow. So I'm a little confused (not unusual)!

Which was why I was wondering if I should add another 1/4 into my day, and if so when?

But perhaps you think (theoretically, here, for the sake of compromise!) I should take 1/2 in the morning, for example, and continue as normal from there?

Thanks again for your help, I appreciate your input :-)

shawsAdministrator in reply to Abi-Abster

Yes, I think you might find a benefit.

I shall give you a link. We know a dose of T4 taken today will gradually diminish over 4 to 6 weeks. We also know that T3 is 'quick-acting' in that it is absorbed quickly but as stated above it's Action lasts up to three days once it is in the receptor cells.

If I took three doses per day my stomach would have to be empty each time, remember to take it and I wouldn't feel 'free' as do at present - fit and well. I would also feel that hypo was controlling my life.

I take my dose of T3 once daily and when raising it from 25mcg I was very aware of symptoms and then as symptoms resolved and I reached a point where I felt a bit over-medicated, dropped to previous dose and have remained on it. It is a marvellous feeling to be completely symptom-free if you've suffered symptoms and felt very unwell while still taking hormones.

This doctor would never, ever prescribe levothyroxine, only NDT or T3 for thyroid resistant patients. This is a link and in particular read June 11, 2002

and January 30, 2002


Abi-Abster in reply to shaws

Yes, I caught a glimpse of that Symptom-Free feeling at the beginning of taking the T3. It was glorious!

Very interesting link - thank you. I'd heard about that approach. Lots to think about on there. Thank you!

Have you tried monitoring your temperature & pulse?

I found lesser muscle aches & fatigue a good sign that I was on the right dose, & not getting cold & having an energy crash at 4pm every day. This seemed to lag a few weeks behind increasing NDT that I did every two weeks. I started feeling a difference once my temperature started getting closer to 36 degrees celcius, from my normal at 35.1. The Barnes basal body temperature test ishouldn't be solely relied on, but was useful to me having secondary hypothyroidism which was diagnosed as FM. Prior to THs, my pulse was always rapid, at 85 BPM, but so weak that it was hard to feel.


The Barnes Basal Body Temperature Test

Despite the sensitivity of all the tests the doctors can give a patient today, a mildly hypothyroid or hyperthyroid person can still appear normal in a test. Many people have symptoms and are clearly affected, yet they complain that no doctors will help them. Even if their tests come up "normal", they suffer tremendously with symptoms of either of these conditions daily.


TSH tests and blood tests are useful to help diagnose thyroid problems but should not be used alone. Symptoms are the most important factor. It is rare that a blood chemistry panel shows your true condition because the values measured are only about 30% accurate. It is common for a person with thyroid problems to have a completely normal thyroid panel. This is why the Thyroid Panel is considered by many to be inadequate. It is common for a hypothyroid person to have a low TSH value, which is usually interpreted as hyperthyroidism, not the reverse, despite many symptoms of low thyroid (depression, dry skin, weight problems, chronic infections, female problems, hair loss, low blood sugar, and so on). TSH tests are not as scientifically accurate as they need to be.

There is a sophisticated test to reveal even mild low thyroid and it is the TRH (Thyrotropin Releasing Hormone) test. This test requires an injection, followed by one or more blood draws at 15, 30 and 45 minute intervals. This test is accurate, but is expensive and inconvenient for both patient and the lab.



There is one simple thing almost anyone can do at home to uncover a thyroid problem: Take your own temperature!

The "basal body temperature" test was developed by Broda O. Barnes, M.D. Because thyroid hormone is so vital to cellular metabolism, reduced thyroid function often manifests as deviation in body temperature away from the normal level of 98.6oF / 37oC.

Barnes recommended the following procedure:

Immediately upon awakening, and with as little movement as possible, place the thermometer under the tongue or in the rectum. Leave it there for 10 minutes. Record the readings on three consecutive days at exactly the same time of day.

Note : a modern digital thermometer can give a reading in less than a minute, but it is wise to check the accuracy with a clinical thermometer first, then if deemed accurate it is so much more convenient to use the digital thermometer

If the average temperature over the three days is less than 97.8oF / 36.6oC then, according to Barnes, one may have hypothyroidism.

Where the temperature is consistently above 98.6oF / 37oC this is an indication that one may have hyperthyroidism

The temperature can also be taken by means of placing the thermometer under the arm. In this case readings will generally be lower than oral/rectal readings, and for the purposes of this test a factor of 0.8oF or 0.5oC should be added to the reading when determining thyroid activity levels.

Even if you have had a blood test and were told your did not have a low/high thyroid reading, you might go back and look at the test results again. You may find that your blood levels of thyroid hormones are actually within the so-called "normal" range but below or above the midpoint. If so enormous benefit may be gained from thyroid supplementation.

Your optimum oral temperature should be 98oF / 36.7oC in the morning before arising. Your oral temperature should rise to 98.6oF / 37oC to 99oF / 37.2oC for about 10 hours a day (starting between 8 am and 11 am).

Please note that this test will give a good indication of thyroid problems but is not definitive. Other factors can affect body temperature. Temperature may be disturbed by several factors such as taking readings at different times, alcohol, illness, a restless night, stress etc. If the readings have a base rate in a menstruating woman of 97.2oF / 36.2oC or less, or a constant reading below this in other women, men and children, an underactive thyroid is very likely. An overactive thyroid would be likely in cases where the temperature is consistently above 98.6oF / 37oC. (note: in menstruating women, on day 1 of the cycle on the first day of menstruation, the temperature will be at a lower level, during ovulation the temperature rises and remains at this higher level until dropping just before the next period. This normal cycle will be affected by an underactive, or overactive thyroid and can be used as an effective alternative to blood tests).

A good test time is to take your oral temperature between 11 am and 3 pm. The next time to do this is 20 minutes after lunch which is when your thyroid function should be at its best.

It is important to work on getting and keeping your temperature at 98.6F / 37oC The thyroid system is a vicious circle, one thing leads to another until bacteria, parasites, and viruses attack and cause other diseases and symptoms, including the body's wanting to attack itself. When body enzymes are not at the correct temperature, they don't convert into the correct hormones, which then cause illness. Even if your temperature is normal and you still have symptoms, you may have a low grade infection that is raising your temperature. Symptoms are a really important factor that need to be taken into account. Once the low grade infection is taken care of, you will be able to do the test again and pick up a low temperature.

An Additional Indicator

Pulse Rate as Diagnostic of Hypoactive or Hyperactive Thyroid: Resting pulse taken when you have been sitting or lying down for at least should 5 minutes. If consistently less than 85 beats per minute, suggests, especially if temperature is consistently subnormal, a hypoactive thyroid. (Women must measure temperatures during menses or when they are not ovulating). Pulse rates higher than 85 at rest on a consistent basis may indicate hyperthyroid, but not always and can be the result of infection, food intolerance and excess adrenalin.

Abi-Abster in reply to BadHare

This is useful - thank you. I had known about this method but also forgotten about it!

It's amazing how difficult it is to get an old-fashioned thermometer these days (I imagine the mercury has something to do with it!).

I'll give it a go with the thermometer we have at home. Pulse-wise I'm no good at taking it, so may have to get a machine of some sort to help.


BadHare in reply to Abi-Abster

I used a cheap digital, & took my temperature a few times, first thing. It is usually low, even when I don't feel cold.

I had to rest a necklace on my carotid artery in the gap between my clavicles, to take my pulse. Now it's strong, so now I can feel it everywhere I should. :)

Abi-Abster in reply to BadHare

Ooh, that necklace trick is a good one! Good thinking Batman 🦇

Think I'll follow your lead with the digital thermometer. Can't do much about that these days!

BadHare in reply to Abi-Abster

I've only overdone T3 a little, on a few occasions. the effect only lasted a few hours, aside when I had a temperature from a viral infection. This winter I'll take less if I'm coming down with something.

Good luck!


Why not ask your GP to test vitamin D, folate, ferritin and B12, if you can't afford private test at moment

Thank you Slow Dragon, I intend to ask my GP Although I hate to ask him as he's already dismissed the whole T3 thing and doesn't know I'm taking it. He also read all my previous bloods as 'normal' even though they clearly weren't - especially the iron levels etc!

Since I've been working on supplementation (and I appreciate how essential this is with regards to metabolising T4 and T3) my query is as much about how to increase the T3 dose as anything, and when to know I should stop (in advance of being clearly hypERthyroid by which point it's a little too late!).

Thanks again for your input. I know you're super-busy on this forum!

Marz in reply to Abi-Abster

I take T3 in two hits - one on waking and one before sleeping - seems to work for me. We all have different approaches and need to work out what suits - hope you find something that works for you too :-)

Abi-Abster in reply to Marz

Yes, I currently take morning afternoon and bedtime too.

Will increase morning dose for now, I think, and see how I feel again in a few weeks time...

Hi Abi, sorry you haven't had an answer to your main question, which was about increasing your dose. I don't know loads about it, but what I've always done is to increase a dose, wait 6 weeks, and then have a blood test and adjust the dose based on that. This is kind of the 'conventional' medical approach.

More traditionall, using NDT, people have increased every few weeks without blood tests (as these didn't exist, but also that blood tests are only reliable if you've been on the dose for 6 weeks-ish). But then once you get to quite a substantial dose, slow back down and do something more similar to 6 weeks and test.

Unfortunately this goes slowly, and its definitely the case that you sometimes feel shit on it ;) But with hormones there is no quick system, and it's common to get word before you get better, or have to spend several months testing a regime that isn't working very well. Although I have been very conservative in my own self-medication, with plenty of blood tests, pulse and BP tests, temperatures, symptoms notes, etc.

I will wade in on dose splitting, as a lot of people have mentioned it. I think as all things hormone related it is about trial and error to see what works for you. 3 doses seems a lot of splits for such a low dose. What I did was to start off taking just one morning dose. When my dose was low, this worked fine for me (I'm taking NDT, which is theoretically slower acting than T3). But once my dose got up to a certain level, I started to notice a distinct difference between how I felt in the morning afternoon, and in the evening. So at that point I split my dose in two and had one in the early afternoon. Straight away I felt a big boost in how well I was, including when I was getting up in the morning, after my morning dose. I now split into 3, and have recently started taking my third shortly before bed as it seems to make my sleep better. I feel like on the lower doses I didn't really need the split, because I had a pretty low amount of hormone in my blood all the time. The T4 should also theoretically even things out a little.

If I were you, I'd move it all to one dose, and then stick there for a week or two to see if it has an impact on symptoms. The main benefit of this is that you can eat any time you want, as I find only being able to eat in short slots in the day has a substantial impact on my social life. But also if you base it on experimentation you'll know why you're having each split and how it benefits you.

Something to consider for your dosage is that you may get to the point where you want to reduce your T4 to make space for more T3 in your day. This is probably the biggest reason to have the blood tests. You don't want to be over medicated, so you'll have to juggle between T4 and T3, and the more records and information you have to do that, the better.

Yes, all good stuff - thank you SilverAvo for taking the time to reply.

So yes, I appreciate that getting by without T4 is an option in terms of end goals, but am not sure that's what I need right now - I know a combination of T3 and T4 still works for some people. I'm keeping an eye on the T3-only method though, as it sounds appealing, and intend to at least increase the T3 over the T4.

And it's interesting what you say about dosing; I noticed my afternoon dose has helped that slump too. Its useful to have heard your methods and I imagine I'll end up doing something similar.

For now, going on what people have suggested above, I think I'm going to increase the morning dose to a half, then look to increasing my afternoon dose to a half also. Likewise the evening. This is because I think I need a considerable increase over all (but because of the ME and being super-sensitive to everything I need to go slow - including taking big doses at once), so will be in a similar situation to you by the end.

Always good to hear other people's experiences and corresponding opinions. Thank you!

Hi Aby,

I've just gone back to look at your previous post with the blood results. It's true that they're low and could do with a substantial increase, but they're not completrly out there.

At the moment you've had a substantial increase, 18.75mcg of T3 a day, which is the equivalent of about 75mcg of T4. So you've doubled your dose over about a month. This is actually a huge amount! Before I did the maths I hadn't realised! If I were you I would definitely stick with this for at least 6 weeks, and I'd strongly suggest sticking with it until you can afford to have a blood test. Adding any extra in addition to this is a serious business, and it can take the body months to really get used to a new dose.

As I understand you're hoping to add an extra 18.75 per day on top of what you're currently taking? I think if I were you I'd be much more cautious, and take it one increase at a time. T3 is very strong, and it can be hard to increase slowly because the tablets are actually pretty massive!

The thing I was trying to say above but maybe not clear is that if you want to increase your T3 by any more, you may need to decrease your T4 by an equivalent amount. So for example if you want to add 6mcg of T3, decrease about 20mcg of T4 at the same time. This will give you a small increase in dose. Although this is kind of all guess work - there is not true equivalency between the two.

It's only by having a blood test that you can make the judgement of whether you're safe to add an extra 6.25 of T3, or whether you need to reduce the T4. This is very much just your own decision, an experiment, rather than any test telling you what you have to do (unless your freeT3 is already over range). But without the test you're making the decision fairly blind.

Just to give you an indication of what I do, I currently increase my dose by about the equivalency of 9mcg of T3 ( I'm on NDT), then stay on that for 6 weeks and retest. So the amount you've increased in a month, I would have done over 3 months and would have two blood tests to look at.

I consider my increases to be quite large, as I've kind of established that I'm going to be needing a quite high dose, and smaller increases were no longer increasing my freeT3 at all. I started out increasing smaller amounts, the equiv of 4.5mcg of T3 every 6 weeks.

Edit: Just gone back and seen it may be 6 weeks that you've been adding T3? I think what I've said still stands, this is a very quick increase.

Hello again!

Thanks for your extra two comments, and for taking a look at my original bloods - you're so thoughtful! :-)

So, i started taking T3 on 25th July, adding in an extra dose when I felt the last had settled. After the first morning 1/4 (6.25mcg pill), I had a good few weeks before adding the second 1/4 at night, and only recently added the third 1/4 dose at teatime.

However, I'm just not feeling the benefits as I did in the beginning (I realise this is all relative, and I am still much better than I was before starting on T3 - still cause for celebration 🎉 but also for further dose tweaking!) Unfortunately, I'm in so much pain again, and my nails are so flakey, that I can't help but think I could still do with some more T3. I feel hypothyroid and grotty again (though not as bad as I was originally).

So, seeing as I was undermedicated anyway on T4, I thought it might be ok to add a fourth 1/4 dose in soon - but this will still be before I'll have the money for a blood test.

I totally get what you're saying with regards to increasing amounts slowly, and agree wholeheartedly. And thanks for your concern but don't worry, i am very conscious of not overdoing meds because of the ME: I know it'll backfire if I try and run before I can walk, so to speak (literally and metaphorically)!

So just to clarify, I'm not 'hoping' to add any more T3 or to reach any particular dosage - I just want to feel OK and in less pain! That was me asking for hypothetical examples of how I might make more doses work in the near future. That's partly why I asked this question; to know when to increase the doseage *safely* in the absence of more recent blood test results.

Apart from being ill with ME/ CFS for half my life (20 years now!) and totally unable to work for 15 of those, more recently I've just lost a year and-a-half to the worst health I've experienced since first getting ME, and it's entirely due to my thyroid.

What I mean by telling you this, is that I have a lot to catch up on in terms of being under-medicated for my thyroid (I've been on T4 for 15+ years, it hasn't been working for a loooong time): I know what being hypothyroid feels like - and I'm still right in it with a long way to go. But, I'm so thankful to have felt that first shift. The wonder of glimpsing what it could be like when my thyroid worked properly (which I caught when the T3 first kicked in and I finally began to feel better)!

And yes, many years of mis-treatment of the thyroid will mean a lengthy time before it's back to normal and at a healthy level. I guess I just hoped it would stay better, rather than settling back down so quickly and feeling symptomatic again. Hence wanting to increase sooner rather than later...

But you're right, slowly, slowly, catchy Thyroid! 🐒

I definitely relate to all the things you're describing about illness and the feeling of impatience.

But I'm not entirely sure it's possible to increase safely without blood tests, especially not at the very fast speed you're wanting to go at.

Oh, actually in answer to that specific question, pulse and temperature and any other measurements you can take will all give you extra clues. If I were you I'd take measurements every day. I used to do that when I was first increasing, and I could see that it all became very chaotic for several weeks after the increase, but then eventually settled down. Previously my pulse was constantly increasing as my dose increased, but with the last increase looks like it is dropping, which is very positive.

Also of course all the reading you can find. You will find all different people gave different protocols for how to raise.

Although if I were you I'd hold now until I'd saved the money. If that's two or three months that's ideal, as it would give all these increases a bit of a chance to settle down. You can get the thyroid panel on Medichecks for £39, I believe it's often reduced to £29 on Thursdays.

I hope this doesn't come across as rude, I think we've got very different ideas about how fast to go, and of course you should do what you think is best. These are all very hard decisions to make, and there are no right answers.

Not rude at all! I wouldn't ask if I didn't want or need telling 😉

It's less impatience and more the unexpected return of my more obvious hypo symptoms that made me think of increasing sooner.

But I'll stick with where I am for now. Thank you for pointing all of the above out!

And yes, I know about Thyroid Thursdays but £30 is also beyond us right now (overspent on supplements)!

Take care,


Good luck! Let me know how you get on. Hopefully you will continue to get improvements while sticking on the same dose. That is what's always happened for me :)

Sounds like that's the protocol to follow, rather than the 'more is more is more' attitude!

Hehe, I definitely know the allure of that feeling!

I agree, it really does seem like you’ve upped your meds a lot and fast, and all advice is to give your body some weeks to acclimatise and for the full benefits to be felt.

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