T3 Result high, but Feeling Fine: Hi, my last... - Thyroid UK

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T3 Result high, but Feeling Fine


Hi, my last blood tests results are:

Cortisol 274 (170 - 500),

T3 - 6.9 - (4-6.8)

TSH - 0.02

T4 - 15.9 (12 - 22)

I had doubled my T3 medication and wanted to check my levels were okay. The doctor was initially worried about the low TSH, but after I explained why it would be low, he said it would be to prescribe the new higher dose, even though the T3 result was just over the top of the range.

Well, I started to feel a bit more tired again, so upped the T3 meds again....now it's a double dose (80mcg per day). I'm feeling fine, losing a little weight for once, and able to function normally. I must assume my T3 result would come back as very high and if I request a test, and if so, the doctor might not prescribe the new higher dose. I want to be monitored, but not sure what I should do at this point....any suggestions please? Many thanks.

Iron - 75 (13 - 200)

21 Replies


Are you also still medicating Levo ? Did you take T3 meds before this test ? If not I would say T3 level is a little high.

You were medicating the equivalent of 160mcg T4 a year ago. 80mcg T3 is equivalent to 240mcg T4. Sometimes it is better to make the replacement meds work as opposed to just adding more. Too much hormone will be destructive as can misbalance others hormones creating further issues.

Are you supplementing iron as levels are still too low after a year and will impair conversion of T4-T3 and decrease deiodinase activity resulting in conversion to reverse T3 (if you are medicating T4 or have an activity left in your thyroid gland). If you are having problems raising iron levels, you could look into gut issues and absorption problems, common in people with hypothyroidism. What about Vit B12, Vit D and folate levels ? ? ..

Long term elevated T3 levels will encourage bone absorption to exceed production with a net loss of bone mass, encouraging osteoporosis. High T3 may also increase blood sugars encouraging insulin resistance.

It will also increase thyroid binding globulin (TBG) to transport T3 to the cells for use but too much TBG will bind too much T3, stopping it being free, so unavailable for use. This will also upset balances of other hormones as they will become bound too.

Many members (including myself) found multi dosing T3 to be beneficial as will reduce the rapidity of onset and prolong the duration of its action.

forever_tired in reply to radd

Thanks for taking the time to reply. Some interesting info there!

Yes, I'm still on 100mcg levo (although it's probably not doing much). I didn't take T3 before the test, I left a 24 hour gap.

Not sure what you mean by "Sometimes it is better to make the replacement meds work as opposed to just adding more"? As as far as I felt, the replacement meds had not worked, or did, then stopped.

I tried to take iron supplements, but couldn't get a high enough dose to make any difference without prescription...and now the doctor won't prescribe any more as it is higher and "in range". I wat loads of iron rich foods too.

B12 and Vit D was very high in range (don't have the results to hand, but I rememeber they were good - due to supplementing).

I take the Linothyronine 4 times a day, every 4 hours.

I think I should get more test done to help with supplementing.

radd in reply to forever_tired


You are now medicating the equivalent of 340mcg T4. That is quite a lot.

Was your test performed before or after you raised T3 to 80mcg ?

For many, thyroid meds will only work well with certain optimal nutrients & iron. Your ideal replacement dose may be lower but meds are not working at a lower dose because these needs are not been met.

Taking too much thyroid hormone may make you feel well short term but can unbalance other hormones and any unused will have the risk of converting to RT3.

Your iron is too low. I don't supplement iron but many members have had success with Ferrous Fumarate when taken with 500mg-1,000mg vitamin C to aid absorption and minimise constipation (or Apple Cider Vinegar).

forever_tired in reply to radd

Test was performed while on 40mcg dose, I've increased gradually to 80mcg since then. I'll try the iron again, like you suggest, thanks. Do you know if I can get a test for RT3? That may be useful to see what is happening.

radd in reply to forever_tired


If you have since added another 40mcg T3, one could safely assume that your T3 level to be well over range.

Reverse T3 may be tested using the link below but is immensely difficult to interpret. Reducing T3 meds would be prudent to lower negatively high levels.


Private labs testing



Negative side effects of high T3.


forever_tired in reply to radd

Well, that's worrying. But, I'm not suffering anynof the side effects (yet). I'm going to come clean to my doctor and ask for help in a holistic approach. Lets see where that gets me....

Thanks again for the info radd. X

So, you were on 40 and you increased it to 80??? That's much too much, too fast. You should increase by tiny amounts, not doubling the dose. That way you miss your sweet spot.

I don't know what to say to you, it's a dangerous game you're playing there. I can only suggest you go back to your last dose, and start increasing by about a quarter tablet every two weeks. These are hormones you're dealing with, not aspirin.

Sorry, I forgot to mention I have increased very gradually - quarter of a tablet for a few weeks then another quarter, until I have found myself now on 4 tablets a day - spread throughout the day.

Ah, ok! lol That sounds better. Even so, if your FT3 was slightly over-range on forty mcg, it's going to be hugely over-range now. Unless you took your T3 on the morning of the test... did you leave a gap of 12 hours?

Yep, I left the gap. I'm still taking 100mcg of T4 a day too ( although I guess it is working less and less the more T3 I am taking). From reading stuff about medicating on T3 only, it seems that it is very symptom led, rather than test result led, since the blood test can't see what's happening on a cellular level....

That is very true. But your doctor is probably going to freak out big time next time he does your labs! lol

Tell me about it! Lol. That's why I don't want to get tested...but I have to let them monitor me, not just for me, but we want to get pregnant again 😬

Ah, ok, so yes, you have to keep being monitored! Well, good luck with your GP! :)

Thanks 🙂


You increase your risk of developing atrial fibrillation and/or osteoporosis by having high FT3. Your FT3 was mildly over range on 40mcg T3 but will rocket on 80mcg. Over medication can also cause fatigue and weight gain. I experienced considerable hairloss when my FT3 went over range.


Thanks for the info. It's so confusing. As I was saying to GreyGoose, the stuff about medicating on T3 is mostly about symptom led medicating, not result led, as bloods don't tell you about cellular functions/ levels....


The same could be said about Levothyroxine. I believe dosing should be guided by symptoms and blood results.

TSH is NOT a thyroid hormone and you should not be judged by it.

Thanks for replying Sandy. Your comments are very positive, and make sense. I have been paying close attention to how my body feels as I've increased my dosage, and I really have found no adverse reactions. I am aware that these may take time to manifest, however, anyone I've spoken to who has been on a too high a dose, has felt palpitations and increased heart rate, pretty quickly.

My father was diagnosed with hypothyroidism a few years back, and is on 150mcg of levo, and my mother has fibromyalgia. I suffered from depression during my late teens (well it was diagnosed then), and although I was only medicated for a year or so, I continually work on this myself with cognitive therapy excercises (my dad was a psychologist so gave me some information to help without meds).

I'll look into Dr Lowe's work, and hopefully be able to show it to my doctor.

Many thanks! X

I tried to take iron supplements, but couldn't get a high enough dose to make any difference without prescription

You can get prescription-strength iron tablets without prescription in the UK, you just have to know how and what to ask for.

Just for your interest, if your doctor was prescribing for you, this is the information he relies on to decide what he can prescribe :


I'm going to assume that you want to buy ferrous fumarate (only because it's the one I know about and could tolerate).

Go to a pharmacy. Ask for ferrous fumarate 210mg in a box of 84. If the pharmacist doesn't quibble then you don't have a problem. If they tell you that you must have a prescription (Boots often say this, so avoid them), then go to another pharmacy chain. I got ferrous fumarate with no problems from Lloyds and Tesco Pharmacies on many occasions.

It is possible to get ferrous fumarate 210mg online apparently, but I've never tried this.

84 tablets is sufficient to dose yourself with 1 tablet, 3 times a day, for 28 days. Obviously you can take fewer than that, but you should not try and take more. To increase absorption you should take each iron pill with 500mg - 1000mg vitamin C. This also helps to stave off constipation which is a common problem with iron supplements. If you get diarrhoea instead, then lower the dose of vitamin C.

Iron is poisonous in overdose and regular testing is essential while you are supplementing. You doctor might help, but since he isn't prescribing I wouldn't bet on it.

You should be aiming to get your ferritin level up to approximately the middle of the reference range, so yours isn't drastically low. You probably need to get up to a level of about 110 on the basis of the reference range you have quoted.

To get tested privately, you would need to pay for a finger prick test.

For a ferritin only finger-prick test I would use Medichecks :


But I really think it would be better to get the full iron status test, at least for your first test, just to check for any oddities in your results :


Good luck. :)

Brilliant info, thank you very much! 🙂

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