T3 Above Limit: Ok or not?: Hi My recent FT3 test... - Thyroid UK

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T3 Above Limit: Ok or not?



My recent FT3 test shows my T3 over range. I am seeing my Endo next week, and fully expect him to have a hissy fit when he sees it lol (if I tell him)

After a few years of hypothyroid symptoms despite good T4 levels and low TSH levels (on 225mcgs Levothyroxine/day), I added T3 to my medication myself (25mcgs/day). The results have been amazing, all my Hypothyroid symptoms have fully gone after 8 weeks of T3. Quite shocked at how good I now feel. Below is todays blood results (patient feeling good):

TSH: <0.01 mIU/L - Range (0.27 - 4.2)

Free Thyroxine: 22.3 pmol/L - Range (12 - 22)

Free T3: 7.7 pmol/L - Range (3.1 - 6.8)

Blood results from 8 weeks ago prior to addition of T3 (patient feels terrible):

TSH: <0.01 mIU/L - Range (0.27 - 4.2)

Free Thyroxine: 23.1 pmol/L - Range (12 - 22)

Free T3: 5.5 pmol/L - Range (3.1 - 6.8)

Patient history is 25 years since Hypothyroidism diagnosed and treated. All good until dose reduction in 2014 (T4) which caused hypo symptoms, dose reinstated a year ago but no recovery from hypothyroid symptoms until T3 introduced recently. Vitamin D, B12, Ferritin all at good level.


I have no symptoms of over medication at all at present (well not yet) and wonder if it is best to reduce T3 and feel unwell, or stay on current dose and risk health issues (if any) and the obvious wrath of my GP/Endo :D lol :)

17 Replies


FT3 should remain within range.

If you left 8-12 hours between last dose and blood draw you are over medicated and should consider reducing T3 dose to 18.75mcg (3/4 of a tablet).

If you took T3 prior to your blood draw FT3 is over range because the T3 peaks in your system for up to 6 hours.

DavyB in reply to Clutter

Left 24hrs prior to blood test as per usual :(

I agree T3 dose needs to come down by looks of it sadly :( Will try reduction and re-test in 8 weeks. Unless, my Endo comes up with anything :)

Thank you again for your help Clutter :)

greygoose in reply to DavyB

If you left off the T3 for 24 hours, then your FT3 is actually higher than that. It's 12 hours for T3, and 24 hours for levo.

DavyB in reply to greygoose

Thanks Greygoose. As others have advised reducing T4 instead of T3 i was planning on dropping T4 in stages to probably about half my current dose hopefully with testing at stages. Guess this will bring T3 down too?

greygoose in reply to DavyB

Depends how good your conversion is. You'll have to try it and find out.


I have a different viewpoint, in that the blood tests were introduced for the use of levo alone. Therefore, if we add into the mix T3 or NDT the results wont correlate.

This doctor was concerned only on his patients' wellbeing.



The fact that you feel so well must be the 'proof' of the pudding. :)

I think I'd be minded to reduce my levo dose rather than my liothyronine dose. Try reducing the levo dose by 25mcg. That should bring down FT3 and FT4. It's probably the liothyronine that's made you feel so much better.

humanbean in reply to Jazzw

I second what Jazzw has said. I'd reduce Levo by 25mcg first then re-test in 6 weeks.

I like that idea Jazzw and Humanbean :)

I had not reduced T4 dosing yet, but it was planned :)

Yes, if you like the T3, then why not reduce T4? I was on T3 only for nearly fifteen yrs as cannot convert and the only way to keep my tsh within range was to have high T3 levels - always between 7-9 with no adverse symptoms. But my T4 was very low and tsh between 0.7 and 1.5. This never seemed to cause me any issues and was the only way to feel reasonable but I had lot of other problems and systemic inflammation at the time meaning I probably had difficulties utilising the T3 or some form of resistance. Since these other issues have cleared up, I've become extremely hyper and sensitive to high levels of T3 and can no longer cope with them. However, you're tsh is suppressed probably meaning that you shouldn't be on such high levels either :-)

Just to update everyone on this issue :)

Saw my Endocrinologist today, and he is confident that I have an issue with my thyroid receptors in my body cells: not absorbing T3 well. Plenty of hormones in blood but Hypothyroid symptoms in patient.

He is not sure what caused it over 3 years ago, but it explains all the odd blood results over that period and the remarkable recovery after my addition of T3 to my daily medication recently, which he was happy with and would have suggested same treatment.

After an examination of me: pulse, blood pressure, looking for hand tremors, etc, he agrees with what is discussed here: I am slightly over medicated.

He suggests reducing both T4 by 25mcgs/day and reducing T3 by 12.5mcgs/day, Retest in 8 weeks, and back for consultation. Bone density scan booked for 12 months time too.

As he said, no idea what caused it but easily addressed with self medication of T3.

I may have to research thyroid resistance myself too, as I believe everyone should own their complaint :) Unless, anyone wants to chip in here with any helpful info.

Thanks again all, dont know how i would have coped over last 3 years without my team: you guys :)

SlowDragonAdministrator in reply to DavyB

sounds like far too much of reduction in T3

what are your levels of folate, ferritin, B12 and Vitamin D - if low these will be slowing thyroid utilisation at cell level

I would drop T4 by 25mcg and retest at 6 weeks - then if FT3 still high tweak downwards

Usual advice is never change two things at once

DavyB in reply to SlowDragon

Hi SlowDragon

Well the reductions in either and/or both in various steps ALL led to Hypothyroid symptoms :( The only way I feel well is with both doses as before and T3 being over range :o Got a DEXA scan tomorrow, and then will be back to see my Endo to see whats next. Folate, ferritin, B12 and Vitamin D all good as were checked first :)

SlowDragonAdministrator in reply to DavyB

Your FT4 is a bit high. You might find you could tweak down by 12.5mcg by alternating 200/225

Just to keep endo happy

Sorry to butt in but can anybody answer my issue.

I am on no medication for thyroid. Have had hashi type symptoms for years. Have a mirena coil and use estrogen gel topically.

My t3 is 7.5 (range 3.5 - 6.2)

How can I be sure what is measured in the blood is getting to the tissues/organs?

Is it true too much t3 causes weight gain because I have gained a stone since replacement mirena 20/12/2016. (My other levels are in my earlier info)

Doc not bothered about above range, I still have aching, fatigue, anxiety, dry skin and hair, palps, cold/heat intolerance, tinnitus, muscle and joint pain, disorientation,, (eye twitch since anesthetic for hysteroscopy and new mirena).

Can't find an answer on the net for naturally above range T3, only med related. Can anyone help please?

Hi Essjay

Maybe start a new post for this question so more will see it?

I have no idea myself on naturally raised T3 sadly as mine was down to medication. However, mine was 7.7 and my endocrinologist didn't really panic at it, just suggested we should try to get it within range.

Essjay16 in reply to DavyB

DavyB, thanks for yr reply. Yes, you are right. I will have a go.

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