Thyroid UK
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Recent blood test after starting t3 advise please


I have rectify added t3 into my regime and stuck with it for 6 weeks.  I only take 2.5mcg every morning with 75mcg of levothyroxine. Before my blood test I missed my normal dose of t3

Tsh 1.99

Free t4 18.1 in range from 12 to 23

Free t3 4.1 in range from 3.1 to 6.8

I feel ok but still have chronic insomnia! Energy levels are very good and I have had a huge improvement in my constipation since adding t3 

I did take an extra 2.5mcg of t3 at lunch for two weeks as my energy levels were originally dipping then but found I was just too wired at night more so than normal and in the end I didn't seem to need it as energy levels have reverted to normal without needing t3 in afternoon. I think my body just needed to adjust.

Anyway based on my test results my t3 level isn't great.

Is there any harm in one dosing and taking the full 5 in morning of t3?

Also next on the agenda is trailing just my t4 after dinner to help with sleep 


6 Replies

Your T3 dose is extremely small. You can take the whole T3 dose with levo in the morning.

You did say "Before my blood test I missed my normal dose of t3' - does that mean you took levo before the test?

1 like

Yes I took Levo but no t3 and I am taking vid d and added selenium in every day for 6 weeks thanks for your reply. Would you recommend 5 of t3?


Don't take any thyroid hormones levo, T3 or NDT before a blood test. 

The test should be the earliest possible and don't eat before it.

There should be approx 24 hours gap between hormones and test. It can skew the results and the GP might adjust dose (down) unnecessarily.

I'm not medically qualified so cannot recommend increasing dose of T3 but I can say what I'd do personally and that is I'd raise T3 dose.

5mcg of T3 is equal to around 15mcg of levothyroxine.


Just to note before the t3 I was on 100 levo only and my blood test was 3.43 tsh and a free t4 over range at 23 and free t3 of 4.5. My t3 level has dropped to 4.1 since adding t3 and dropping levo and free t4 dropped to 18 and my tsh has also dropped to 1.9 the results don't really make sense? 



You reduced Levothyroxine by 25mcg but only replaced it with 2.5mcg T3 which is equivalent to 7.5mcg Levothyroxine and that's why FT4 and FT3 levels have dropped. 

You'll probably need more than 5mcg T3 to get FT3 5.5-6.8 which is good for most people.  5mcg is a very small dose so you can take it with Levothyroxine in the morning.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

1 like

Taking T4 before your blood draw won't show accurate labs Bubbap



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