T3 too high!: Hi everyone. I've been feeling... - Thyroid UK

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T3 too high!

infomaniac profile image

Hi everyone. I've been feeling really poorly for weeks now and have just got my blood results back

TSH 0.01 (0.23-5.50)

Free T4 1.08 (0.23-5.50)

Free T3 6.11 ( 2.00-4.40)

Obviously my T3 is WAY too high and my T4 seems very low.I need to get the T3 down ASAP so can anyone advise me how I should go about this please? I'm on 100mcg each of T3 and T4 and have been decreasing T4 whilst slowly increasing T3 but sadly my plan didn't work!

I don't know if it's a coincidence but I only started feeling weird after having the worst hangover I'd had in decades in November. Could there be a link?

I've found my Folate is right at the bottom of the range so I'll be tackling that as well :-)

43 Replies
SeasideSusie profile image


Why are you taking such a high dose of T3? It's obviously too much because of your over range FT3 result.

Is there a reason you're decreasing your dose of Levo?

When on a combination of Levo and T3, it involves a lot of gradual tweaking to find the right balance that suits you. Looking back at a previous post you've gone from 12.5mcg T3 to 100mcg T3 in approximately 5 months. Have you not kept an eye on your levels when you make a dose change?

I feel so stupid but what has happened the last 2 times I've had my blood taken is I've messed up skipping a dose so I wasn't really sure what my correct level was. I wanted to try and reduce my T4 as people on T3 only seem to fare better. I increased my T3 in July but still didn't feel 100% so I increased again in September. Everyone seems to suggest leaving 6 weeks between increases so I thought I was doing the right thing, especially since I was decreasing T4 at the same time :-(

I live in Spain so keeping an eye on things is just that bit harder but I've learned my lesson now.

SeasideSusie profile image
SeasideSusieAdministrator in reply to infomaniac

I wanted to try and reduce my T4 as people on T3 only seem to fare better

Some people fare better on T3 only, but we have to find out by trial and error. There are far more members on combination Levo/T3 or NDT than there are on T3 only.

That's why I haven't given up on T4 totally. I'm not sure why it's so low when I'm taking 100mcg though?

What do you suggest I should do to get my T3 down Susie? As I said I like to do things slowly but I am desperate to get rid of this constant dizziness.

SeasideSusie profile image
SeasideSusieAdministrator in reply to infomaniac

Well, any change in dose should be gradual, 25mcg for Levo and 6.25mcg for T3 is what's normally recommended, so I honestly don't know what to suggest with such a high dose of T3, maybe you could reduce by larger increments, but I really have no idea.

Is there any possibililty the dizziness could be connected to low B12, or BPPV (Benign Paroxysmal Positional Vertigo)?

Funnily enough that's what I thought it was. Someone suggested that on a FB group so I bought a book about B12 (glad I did too) and was convinced that's what it was. I'm not 100% sure exactly what the status of my B12 is as I've been supplementing anyway and apparently you have to stop for months before you can get a true reading-which doesn't sound like a great idea. I found out today my folate is right at the very bottom of the scale so perhaps my B12 is too.

I think I'll reduce my T3 by 6.25 and see what happens. Do you have any idea why my T4 is so low?

SeasideSusie profile image
SeasideSusieAdministrator in reply to infomaniac

Do you have any idea why my T4 is so low?

No, other than you are taking such a very high dose of T3 and you probably need a better balance of Levo/T3. Taking T3 tends to lower FT4 (and TSH), but as with everything it's all very individual.

I have been taking T3 with my Levo for almost 3 years. I went from 175mcg Levo with a way over range FT4 - 165% of range - and FT3 at 55% of range, to now being on 112.5mcg Levo plus 18.75mcg T3 and it gives me FT4 and FT3 around 75% through range, which is where I seem to need to be with my thyroid hormones. Other people feel well with a lower FT4.

However, it took about 2.5 years of tweaking doses, retesting, assessing how I felt, optimising nutrient levels and addressing adrenals (these I found to be key to helping me find the right amount of thyroid hormone, it just wasn't working properly when these two things were haywire), before I finally found what suits me best. On this journey my Levo has ranged from 75mcg to 125mcg and my T3 has been at various doses to as high as 31.25mcg before I found what seems to be right for me.

Please see my reply to Shaws. I made a HUGE error in stating what my dose was :-(

SeasideSusie profile image
SeasideSusieAdministrator in reply to infomaniac


So if those results are from when you were taking 100mcg of T4 and 25mcg of T3, basing it on my experience, you need less T3 and more T4. You may feel better with a higher FT4 and your FT3 in range. BUT when did you take your last doses of Levo and T3 before this blood test? Did you leave 24 hours for Levo and 8-12 hours for T3.

Yes I left the correct amount of time before my test so the figures are correct.

SeasideSusie profile image
SeasideSusieAdministrator in reply to infomaniac

So the first thing I would do is reduce my T3 by 6.25mcg and give it a few weeks then see how you feel and I'd retest then reassess.

Thanks I will do that and hope everything rectifies itself quickly :-(

I too am slightly too high in T3 with NDT. I've been feeling yucky for weeks. I'll be decreasing my dose and seems like you should do the same. You should be taking a ratio of T4 to lower T3.

Can you lower the T3 to 25mcg? Perhaps increase the T4 if needed?

infomaniac profile image
infomaniac in reply to Boon79

100 to 25 sounds a bit drastic? Believe it or not I like to do everything really slowly! I don't really want to up my T4 but not sure what to do as I don't understand why it's so low.

Boon79 profile image
Boon79 in reply to infomaniac

Moving from T3 to T4 isn't usually a problem but caution should be taken when increasing T3. Sounds like you need to increase T4 and decrease T3.

infomaniac profile image
infomaniac in reply to Boon79

That's exactly what I didn't want to do! T4 has never really done much for me but I was OK with keeping a little bit but it's all gone pear-shaped :-(

It's gone pear shaped because you don't know what you're doing, to be blunt, you are going to make yourself really very poorly if you are not careful.

Thanks for that vote of confidence! I have done my best considering I am self medicating and unfortunately have nobody to go to for advice other than fellow sufferers online, so please don't kick me when I'm down. I started out on T3 and stayed on that dose for ages until eventually increasing to 12.5, and again staying on that dose for a good while until I decided to reduce my T4 from 125 to 100 and increase my T3. My only error was not getting tested prior to my last increase but that won't ever happen again I can assure you. Incidentally I went to my doctor (I live in Spain) regarding how I was feeling (dizzy, shaky, palpitations etc) She took my blood pressure and gave me an ECG (both normal) and has referred me to a Cardiologist next week. She knows I'm on T3 and we even spoke about it but she did not pick up that my problems were down to my T3 being out of range...so if a doctor can't pick up on that (and didn't even test my T3, only TSH and T4) I don't really think it's that bad that I didn't either!

I thought you were taking 100mcg of T3 which is an insane amount for anyone to take so I was going off the basis of your OP, i have commented elsewhere.

Yes..a bit of a faux pas on my part! I am grateful I'm not on 100mcg if this is how I feel on 25 :-(

shaws profile image

I think you've made a mistake of 'assuming' that 100mcg of T3 is equal to about 100mcg T4. T3 is at least three times stronger than T4 and it is no wonder you don't feel good. 25mcg of T3 is equal - in its effect - to 100mcg of T4.

My dose of T3 is about 37.5 and I'm well. I take T3 alone.

Your dose of T3 equals approx 400mcg of levothyroxine plus 100mcg of levo - 500mcg daily!!!!

infomaniac profile image
infomaniac in reply to shaws

OMG! I think this T3 has affected my flipping brain, or what's left of it!! I'm actually on 100mcg of T4 (reduced from 125mcg) and 25mcg of T3. So sorry for the mistake. I decided to reduce T4/increase T3 after "talking" with you and you said you were well. No wonder people think I've been doing things too fast!

Ah ha! That makes more sense.

I've had a Free T3 which was far too high in the past. Before testing I had assumed I would be under-medicated, so I got quite a shock when the high result came back. I stopped my T3 dose for a few days - until I felt mildly hypo, which didn't take very long - maybe three days. Then I restarted on a slightly lower dose.

I was very reluctant to lower my dose of T3 because I was convinced I would feel awful. But much to my surprise my brain fog lifted when I lowered my dose. So, for me at least, I get brain fog when over-dosed and when under-dosed.

infomaniac profile image
infomaniac in reply to humanbean

Interesting! I have had permanent brain fog ever since I was diagnosed...I'm getting used to it now :-(

Hi, I went over at first whilst I was titrating up. I did same as Human Bean, left it a couple of days and then resumed at a slightly lower amount. It is my understanding that T3 leaves the body quickly. I take NDT although have experimented with some Turkish T3.

Re your folate- take 400mcg a day and aim for a level of about 15. You will be surprised how much different you will feel.

You said you had been supplementing B12 - it is important to take B’s in balance. What have you been taking? Can you get tested to see what your levels are? I am surprised they weren’t done at same time as folate.

What happened was I had been feeling absolutely dreadful for about 5 weeks and couldn't work out what it was (I had increased my dose in September so didn't make the connection.) Someone on a FB group thought it might be B12 and it all seemed to fit. The only thing was that to find out if it was low I'd have to stop supplementing for months till it was out of my system so I got it tested anyway and it was at the top of the range, but since I am supplementing that's not surprising so maybe if I wasn't it would be low? Who knows! When the doc did my bloods she also did homocysteine which was out of range so a bit of a worry. So I boned up on that and found B12 B6 and folic acid would bring it down so trying to be careful I thought I'd get my folate tested and it was scraping the bottom of the range and that's when I also found my T3 had rocketed! I have reduced my T3 by 6.25 and have split the dose into three to try and space it out a bit. I was a bit scared to go cold turkey and do without it altogether.

Who on earth told you to stop taking B vits to test them? It sounds like you are running around some dodgy forums getting duff advice! T3 is an incredibly potent hormone, not to be messed with, and using to good effect requires diligent, disciplined, knowledgeable action. It's not to be messed about with. You need to regroup, understand what you are doing, and proceed very gently, there is a process to getting your ducks in a row.

I seem to have read a few times that it's hard to get a correct B12 reading when you're supplementing? I have always proceeded very slowly with T3 and have never had any adverse effects until now. If I'd started feeling rough shortly after upping my dose I would have realised that it was too much for me but it didn't happen until some time later.

I think there's an different kind of test for B12 to be absolutely accurate, but I just have about 5 days off iron, B12 before testing. What supplements are you taking, and how long have you been feeling off?

For information This is what I Endo told me when on NDT-the results are read differently. TSH will be suppressed, FT4 can be lower in its range but FT3 should be high but never over. I presume when taking enough T3 our body doesn't need to hang onto as much T4.

Yes that makes sense doesn't it? My T4 has never been this low so I think it's the excess T3 causing it to drop.

T3 doesn't cause T4 to drop, in NDT it's just in different ratios that's all.

I was told that the only accurate reading is the FT3 which needs to be high in its range but that the FT4 can fall as your body in theory doesn't need to store as much as its happy with your high FT3. TSH again is suppressed as you don't need the messenger (TSH) to tell your body to get more T4 as again it is happy with your T3 levels.

How long after your dose of meds was the blood drawn? And you need to regroup and start again. T3 comes out of your body really fast, just skip it for a couple of days, and start again on a new dose. Meanwhile I'd put your T4 back up to what it was, let your body start again, and regroup. T4 has a half life of 9 days, it stays in your system for a long time, but it's essential to lots of things including memory, hair growth, mood etc.

What was your original dose of T4 and T3?

You dont' say whether you are male or female but T3 only is incredibly tough on a female body.

You say your folate is low, where's your iron and B12, ferritin etc? Increasing T3 when iron and b12 in particular are in a mess will make you feel dreadful!



I'm female :-) I left 12 hours after T3 and 24 hours after T4 before my blood was taken. I had planned to reduce by 1/4 of a tablet to 18.75 today and to split it into three doses but after the first one this morning I still feel lousy-really dizzy so I haven't taken another yet but I feel a bit scared of skipping it altogether. I've never felt great on T4, which is why I started on T3 in the first place, and it's never did a thing for my hair, mood or memory sadly. T3 did make me a little bit better in the beginning but I've had loads of issues since so I'm hoping it's down to the low folate.

Folate 2.6 (2.2-15.0)

Iron 143 (37-175)

B12 732 (200-850) and I don't have a ferritin result.

I was on 12.5 but didn't feel great so increased to 18.75 in July then as I was still not 100% I tried another 6.25 in September but couldn't really tell much difference until about 5 weeks ago.

Hiya, you should really have 16 hours between meds and test. Having read all your comments now I realise you are not on 100mcg of T3! Your T3 isn't massively out of range, if you want to get it down, just skip a day with the T3, let it get out of your system and try again. T3 needs to be spaced out through the day so you'd take on waking with your T4, at lunch (and hour before food) and then at about 5pm is on an empty stomach, rather than in one big dose otherwise you'll get big peaks and troughs which will mess with your blood sugar - so you'd use a pill cutter, or smaller dose tablets, say you are taking 25mcg you'd take 10 + 10 +5 over the day. Or some people do better with a crumb at bedtime so you could try 10 + 7.5 + 5 + 2.5 You obviously need to get your folate up (that can be tricky for some people, but that's for another day) and you need to make sure all your other key vits and minerals are optimal, otherwise no matter what you take thyroid wise, you will feel dreadful. So that would be B vits, iron, b12, minerals, magnesium etc. This is called getting your ducks in a row. if you do all the usual stuff and still feel rubbish, you'd look at candida, gut, adrenals etc. if after all that you still feel rubbish, sex hormones, or look at switching to NDT. But systematically so you are ruling things out, and not shocking your body with big changes.

When you say you 'don't feel great' what does that mean? What sort of symptoms are you having? What's your diagnosis? What dose of levo did your doctor start you on? You don't need to lower T4 to add T3, and imho there's a vanishingly small number of people for whom T3 only is better than combo, particularly women.

The thing to really understand with thyroid is we need to be consistent, systematic, and gentle - if you hurl too many changes at your body, or chop and change too much, it just won't cope and you won't be able to figure out what did it.

Thyroid meds will be dosed depending on how hypo you are, your bodyweight, and how you feel.

Hope that helps. Don't over complicate it, it's all quite logical really :-)

For me the obvious solution would be to exercise to use that T3, if you don't want it I will gladly take some as I do not have enough to exercise at all. LOl

If I exercise I deplete my T3 and it takes me days to recover, hence the approach. If you already exercise enough just take less.

infomaniac profile image
infomaniac in reply to Angelic69

I did plan on exercising to see if it would help but I still feel so weird and dizzy. I hope it wears off soon.

Angelic69 profile image
Angelic69 in reply to infomaniac

I've had my TSH suppressed this low and i felt really crappy too, blurred vision, headaches, joint pains, weak and heavy feeling like lead, confusion feeling that only half of me is part of this world and the other half in limbo somewhere.

Although my Doc didn't advise it i stopped my meds for a few days and felt quite well. Then started up again until i felt weird again. Hope this helps.

infomaniac profile image
infomaniac in reply to Angelic69

Sorry Angelica I've only just seen this. I wasn't really thinking about my TSH being a problem, more the high T3 and low folate. I think my TSH might be slightly higher now as I decided to stop my T3 and as it coincided with Christmas I still don't have my blood results, so I've now been off it for two weeks. The way I felt when I was taking too much T3 has made me feel very wary about re-starting it again to be honest but I'll see how things go once I get my results-tomorrow hopefully :-)

You just need to lower you t3 dose. Your T4 will naturally be suppressed if you're taking external T3. That's normal. You probably feel bad from the T3 being a little too high. Your T4 dose is probably too high as well. 25mcg of T3 and 25 mcg of Levo would probably work a lot better.

infomaniac profile image
infomaniac in reply to doude

Thanks Doude. I'll bear that in mind :-) I really would like to reduce my T4 but everyone seems to want me to increase it!

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