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Optimizing T3 and exercise

Not sure my question makes much sense but I am struggling to get optimal results, feel well and live the active life that gives me a sense of purpose. I'm working on adding T3 to my previously T4 only regime. I have been successful in raising D3 and B12, have good selenium and magnesium and am taking zinc with copper as it's currently quite low. My T4:T3 ratio is moving closer to 4:1 .... not there quite yet but I feel better when my T4 is right at the top of the range so my strategy is to only reduce the T4 a little while adding 12.5 mg of T3 AND working to improve conversion. My stumbling block is the fact I have "raging" antibodies....and I can't seem to find out how these link to symptoms, conversion, or medication. All I can do is to use diet and lifestyle to try and bring them under control. But I think it is more realistic to accept that with Hashimotos there isn't much you can do i.e. We treat the symptoms not the cause ! My real dilemma is that the strategy of adding T3 is fine until I want to add exercise into the equation and then it all becomes problematic. Exercise uses up T3, T3 has a relatively short half life (a few hours - less than a day), if you don't convert well exercise can push you into a hypo state if T4 is already top of the range.....so how do I factor all this information to know what to do ? Once I'm within range of a blood 4:1 ratio do I add a bit more T3 during the days I'm active ? How much equates to a bike ride, digging the garden, chopping wood? I do keep a track of both temperature and pulse and I find my temp and pulse are both still low until the afternoon when they just about reach "normal" (37 degrees and 72 bpm). I take 125 mg Levo about midnight before bed and 12.5 mg T3 about 6 am, a couple of hours before I get up. I'm pretty sluggish until the afternoon and that's usually when I get active. (It occurs to me that the body temp rise might be more to do with activity levels than hormone levels...another factor which leaves me slightly confused.) I have noticed that my weight tends to rise after days of high exertion ....I weigh myself every day and I'm only talking about 1/2 kilo max but it confirms a comment greygoose made on another link about exercise creating hypo conditions if one's not careful.

Like a I say, not sure what the question is but I'd be interested in anyone with thoughts to share.....

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Hi wantie I don't have any answers other than the general advice that you will have read re being careful of exercise of high intensity (pretty sure that wood chopping falls into this category) but would be very interested in the comments. Perhaps your latest bloods would be helpful.

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Hi - I added t3 on top of t4 for that very reason. Exercise left me drained and over-tired for the intensity of it. I worked out that, keeping a steady dose of t4, if I became suspiciously fatigued during exercise, I needed to up my t3 a bit. That worked great if I kept up regular, consistent amounts of exercise. However if I missed a couple of days then I had to ease off the dose a bit. The thing I found that helped most was taking my t3 at bedtime along with my t4. It seems to keep me steadier the next day - no highs and lows. I am sure I have seen posts here quoting one of the reference doctors, saying that it is best to saturate all receptors at once, thus having 24hrs coverage for all activities. Just for interest, in my early days of treatment, tests at my gp showed my TSH actually rose from previous despite 25 mcg increase and I put that down to 3 intense exercise sessions in the previous week. So to me, exercise is the equivalent of about 40mcg T4 a day. BTW, I also worked on conversion at the same time and have recently had to reduce my dose because of improvements in nutrients.

But from what you say about being sluggish till the afternoon, it sounds like you might be under-medicated still - do you have any recent results?

Gillian xx

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Many thanks, that is really helpful. I had thought to change my dosing time for T3 and what you say makes sense. I think the metabolism of a normal person shows that T3 peaks at about 2-3 am. I was taking it the morning because I thought it had a relatively short half life and wanted it to work on me during the day instead of at night. However, I think that once you have been taking it for a while the levels in the cells rather than the blood is more relevant and a nighttime dose may be more effective at getting into the cells.....(just surmising....only know what I gleam from this site).

Can I assume that a low waking body temperature indicates under medication? If so, that and morning sluggishness would suggest what ? A bit more T3 or a bit more of both to keep the 4:1 ratio?

When on 150 mg Levo result 07/02/17

FT3 4.17 (3.10-6.8) pmol/L

FT4 22.41 (12-22) pmol/L

TSH 0.27

Dropped Levo to approx 120mg (breaking tabs of 150 and alternating with 125) and added 6.25 T3

Went gluten free and started supplementing with D3, B12 + B complex, zinc and vit C a month later 10/03/17

FT3 4.79

FT4 20.81

TSH 0.07

Stopped T3 (mainly because long term supply could be problematic) kept up the better eating and went back to 150 Levo

Latest 06/04/17

FT3 4.98

FT4 22.73

TSH 0.08

Now, because of the exercise I want to indulge in, I am back to 125 x 4 days, 150 x 1 T4 plus 12.5 T3.

Have to say, get very stiff and achy after even a yoga session. Mowing and digging leave me feeling like an 80 year old. This is what I want to overcome....

I'm also sticking with this for a bit longer as I realise my bloods are only 4 weeks apart. All the best


Hi - it looks to me like you are a bad converter as others have said but you look to be also also under-medicated. Just to confirm my understanding.

all doses total per week and assuming t3 as 3.5 times t4 (estimates vary 3-4)

to 7/2 - 1050 t4

till 10/3 - 840 t4 + 37.75 t3 = 972.15 t4

to 6/4 - 1050 t4

current - 950 t4 (incl 150x3?) + 87.5 t3 - is this one correct? = 1256.25 t4 (I am not sure about your total dose now)

This is only for a rough comparison - for a bad converter this is not a strict equivalence. So you actually cut your total dose in the middle - check current dose and compare. At no point in this have you been anywhere near optimum for ft3 - your highest is still only 50% through the range so you have definitely been under-medicated. Most people would feel better with ft3 about 75% through range - 5.88 here. With the unclear current dose i can't comment on what should happen now, could you confirm how much you are currently taking?

On a separate point of antibodies - many people find being strictly gluten free helps reduce anti-bodies but some, myself included, are also sensitive to the protein (casein) in dairy so have to cut that out too. Addressing gut issues can also help - search within group for threads on healing leaky gut. Sorry I don't have any handy links.

Gillian xx


It's kind of you to help. I'm feeling a bit confused by it all. And now really don't know what to do. But your right, since my last bloods on the 6th it's been a bit random. I've kept the T3 at 12.5 daily but been taking mostly 125 mg T4 and adding one of 150 every three to four days. The calculation is probably more like 125x6 =750 + 150 = 900 of T4 and 306.25 T3 a total of 1206.25

But this looks like quite a jump. Should I reduce the T4 a bit ? Given what you say about converting and my high T4 levels perhaps it's better to reduce the T4 to 100 (I can do 112.5 more easily) as that is closer to my previous total dose. Would that make sense?

And I have been gluten free since Feb and found it sorted my gut problems like magic! Am trying the Hash protocol diet but find it hard. Have said I'll do it for two weeks but probably won't make it. I have never found dairy a problem and cheese is one of my passions.

Once I get a feel for where I want to be and the balance of mess that make me feel well and allow me to do the things I want, I will need to tackle my doc. and see if she will support me. At the moment I'm so at sea, I wouldn't know where to start!

Hope this makes sense



Hi - the normal increase at a time is 25 t4 or 6.25 t3 so no, up to 1206 is only an increase of 150 t4 equivalent per week or 21.5/day so that is a reasonable increase. My main point was that you do need that increase and quite possibly then some more. As you have been on that over 2 weeks now (the recommended dose increase interval when adding small amounts of t3), you could now add a bit more t3 if you still feel under as your stiffness etc would suggest. So maybe hold your t4 as is and add another 6.25 t3. Your reduction in t4 as of 6/4 will have brought your t4 down a bit so I would leave that alone for now. But once you do this increase I would hold that dose for 6 weeks to allow your body to settle then test again. At that point you should then be able to gain a clearer picture of the effect of t3/t4 balance.

good luck

Gillian xx

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Many thanks for your advice. I find that some days I feel confident about what I'm doing and other days I just lose it and want the simplicity of T4 only even though I know that most of my deteriorating health is to do with lack of T3. I have got cynomel without a prescription and have a doctor who wants nothing to do with it. Trying to manage my Hashi condition with the active lifestyle I want appears to be impossible at times. Plus I'm not sure I know how to tell the difference between being over or under medicated. I thought body temperature and pulse rate were helpful indicators....but apparently this is not necessarily so fo Hash sufferers !

I'm going to leave it a few days then add another 6.25 T3 like you say. Can it all be taken at once ? I take Levo at midnight and 1/2 a T3 (12.5 mg) a couple of hours before I get up. I'm tempted to take them both as I go to bed....could the extra dose be included or should I stagger it a bit ? All the best


Hi - when I increased from 12.5 to 18.75 I tried taking 12.5 am and the rest pm. But this gave me pulsatile tinnitus (hearing blood pumping in head) after am dose and kept me up half the night. So I switched to taking it all at bedtime (as I settled to sleep). In that way I am asleep before it starts to hit system but it is into the cells by morning so no feeling of peaks and troughs. But everyone is different and some need to split. I would suggest you experiment a bit, maybe starting with whatever fits best around other supplements, meals etc. Remember 1 hr before food, 2-3 hrs after, 4 hrs form iron or d3 and 2 from anything else.

Good luck

Gillian xx


Your FT3 results are still far too low I suspect. I would not be able to get out of bed on those results. Working on the 3.10-6.8 range I would need an FT3 around 6.3 or 6.4.

So I'm not at all surprised by how you feel. Clearly you don't convert well which is why you need the T3 in the mix.

You are way below a sufficient level. Your FT3 levels aren't even half way up the range.

I would suggest that you Need to increase your T3 dosage until you begin to feel some relief.

Do you have a GP who could coordinate a dose increase?

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I think your right. I'm working on getting my doctor to take some interest. At the moment she doesn't want anything to do with T3. I've managed to get it without her help and now need her to help me monitor. But I am going to add a bit more to see if I feel better. Thanks for your help


Thanks for that, I'm only just beginning to realise the impact of exercise...no GP or endo has ever mentioned it. ...nor the link to diet.....I actually think last year I caused myself all sorts of havoc by starting the 5:2 diet and seriously restricting my calories on top of which I undertook a grueling 500 km bike ride (electric bike so not what it at first seems). That was in the summer, by November I was suffering with IBS, throat and oesophagal (?) throbbing and irritation, acid reflux, and had blood that showed deficiencies in D3, B12, and Zinc along with ATp >600 (<34) and ATg >4000 (<115). That was when I discovered Thyroiduk and my journey of self-enlightenment ! See below for bloods..


Wantie, it's not a good idea to focus on ratios. Ratios are for healthy people. Yes, that's the ratio they have in their blood, BUT healthy people not only have their thyroid glands making T3, but they also convert their T4 without any problem. You are hypo, so you draw a blank on both of those. Therefore, trying to keep your ratio the same as a healthy person will probably leave you worse off than ever. You need to take what you need to take, and comparing yourself to a healthy person is not helpful. :)

Quite apart from that, if you try and stick to the ratio of someone who converts well, when you don't convert well, will be that you will end up with low T3, and a lot of unconverted T4 in your blood. If you have too much unconverted T4 swimming around, it can convert to rT3. And, excess rT3 is really not something you want. So, I can't help feeling that ratios are very misleading, and unlikely to restore you to good health.

T3 has a short half-life in the blood, that's true. But, in the cells, it lasts for several days. So, that's irrelevant. And, don't get hung-up on your temperature, because some people's temperature never rises - again, that's comparing yourself to a healthy person. You are hypo, it might never be the same for you. So, don't worry about it.

How do antibodies link to symptoms, conversion and medication? Who knows! Antibodies can cause symptoms in some people - but who's to know what is antibodies and what is low T3? I doubt there's ever been any research into that. A lot of Hashi's people do convert badly, that's a fact, but why? Once again, who knows. As for 'medication' - thyroid hormone replacement - you need enough to make you well, and that means enough to suppress your TSH, because the less gland activity there is, the less antibody activity there is - so the thinking goes. I can't really comment on that because the time it took me to get a diagnosis - or even a thyroid test! - my gland had already been killed off by antibodies! But, seems like a reasonable theory to me.

So, you've obviously had some nutrients tested, what about ferritin? How is that? It's essential for conversion. You say you take zinc and copper. Did you have either of them tested? It's true zinc and copper need to be balanced, but hypos are very often low in zinc, and high in copper, so taking both of them will perpetuate the imbalance. And high copper is not nice at all!

'if you don't convert well exercise can push you into a hypo state if T4 is already top of the range'

I don't know what you're trying to say, here. Exercise makes you hypo because it uses up your T3 - it's low T3 that makes you hypo, not high T4. The problem is that if you can't convert that T4 well enough, and quickly enough, you become hypo after exercise. Nothing to do with the T4 being high.

As for whether or not you should add a bit more T3 when you're active... Lots of people have asked about that/suggested that, but I've never heard anyone say they actually do it, and how it works. How would you know how much to add? Or, when to add it. I don't think the research, or the maths, has ever been done. And, it seems to me that if you have a good level of FT3 to begin with, and take the right amount of T3 regularly, you shouldn't need to add more in on an irregular basis. Of course, if you want to experiment, please do - you can report back and let us know how you got on, and how it worked for you. But, be careful! :)


Hi grey goose you have thrown another scanner in my works....I thought it was important to take zinc with copper to help it absorb. My zinc is low and I picked a zinc supplement especially in the formulation 15mg zinc to 1 mg copper to get the best absorbtion. Funnily enough it is the one supplement that hasn't yet shown an improvement, both theB12 and D3 did. I thought my ferritin was ok at 60.6 (20-150) and the folate was written > 45.400 (8.83-60.8) and again assumed that was ok.

Your comments regarding my understanding of the importance of T3 relative to T4 are all very helpful. But regards dosing how do I get to a level where T3 is in the upper quartile of the range and my T4 doesn't drop (as it is at the top and needs to stay there) without taking high total amounts of hormone ? Mostly the advise is to drop T4 to add T3 but I don't really want my T4 to drop, do I?

As you can see, I'm getting more confused , not less...

Thanks anyway


If you are taking T3, it doesn't matter where the FT4 is. No matter how much you take - unless you are grossly overmedicated on T4 - the body will just keep what it wants, and it doesn't need as much as if you were on T4 only. So, no, you don't need it up the top of the range.

Copper doesn't help you absorb zinc. Supplements often contain the two in a certain ratio because the two need to be balanced. But, as l said before, ratios are for healthy people. Hypos, for some reason l don't know, are often deficient in zinc, but have high copper, which is the wrong way round. So, they just need to take zinc.

Your folate is ok, but your ferritin could be higher. Aim for at least mid range.

Sorry if I've confused you, but as l said it's not at all good to base your targets on euthyroid people. Hypos are different, I'm afraid.

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I hope you don't mind me quizzing you a bit more as it appears my understanding of all these issues is quite superficial. I had thought that I was aiming for both T4 and T3 to be in the upper part of their respective ranges. I was hoping to add cynomel to a slightly reduced Levo dosage to try and achieve this. Taking all the necessary steps to aid conversion such as no gluten, optimal selenium, zinc, B12, D3 and ferritin and folate at the same time. I had also understood that high T4 can result in high levels of rT3. I have never tested rT3 but was factoring this in to my decision to reduce T4 while trying to boost T3. When I start to change my dose and reduce levo I feel rubbish probably because I am not supplementing with enough T3 to compensate. I guess I'm a bit nervous of doing anything too fast or too much. For instance I will stop my zinc with copper until I know my copper blood level, or at least buy just Zinc....now you have filled me in.

I know the consensus is that everyone is different and it a very personal journey but I'm not sure now what blood results I'm trying to achieve. Is it T3 at the top of the range and it doesn't much matter where T4 or TSH are ? But that total hormone dosage (T4 and T3) should be roughly what makes you feel best ? Is it still true that a very suppressed TSH is good to reduce antibody attacks ?

Sorry for so many questions...your comments are always helpful greygoose

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Ask as many questions as you wish! There's no limit. :)

Yes, high levels of unconverted T4 can result in excess rT3.

If I were you, I would raise my T3 to at least 25 mcg before starting to lower the T4. It won't do any harm to have high levels for a short period.

When you are taking T3, the most important level is the FT3 - especially if you're a bad converter. The high FT4/high FT3 is advised for people on T4 only. When you add in T3, there's no point in trying to keep the FT4 at the top of the range.

When you are on any sort of thyroid hormone replacement, the TSH is irrelevant unless it goes high - which means you're under-medicated. It doesn't matter how low it goes. And, suppressed TSH is still recommended to stop antibody activity.

No-one can tell you in advance, what doses of T4 and/or T3 are going to make you well. You have to find that by trail and error. :)


Wantie great question and greygoose as ever you explain things very well. Just done a bit too much in the garden and was pondering about this very subject - though I'm not yet optimal so it's blue sky thinking 🤔🤗😀


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