Thyroid UK

Started taking t3 yesterday with t4

Had my first go with t3 in combination with t4, I've got 5mcg tablets and just nibbled off about 1.5 mg of the tablet, yesterday as I'm nervous about taking it and how much to take, I had 75mg of Levo yesterday. My pulse is fast at 88 my body temp 36.9 c. I,m wondering whether to take 50mg of Levi today as on my last blood test total t4 was over range at 27. Prob don't even need t4 ? Would swapping to t3 only help? Greygoose suggested I might have high reverse t3 would that affect me taking t3 in such small doses, I had 1 mg of t3 today so far and no Levi, as t3 is very potent. Could I alternate taking Levi with t3 one day and t3 on its own another day?

Bit confused and worried about nasty side effects or going over range on t3, it was 4.8 last blood test.


5 Replies

There is quite a lot of assumptions regarding T3.

I myself had lots of palpitations and was very unwell on levothyroxine only.

When I added 10mcg of T3 to a reduced levo, my palpitations ceased and I felt so much better.

T4 as you probably know has a long half-life and slowly diminishes over several weeks.

T3 is absorbed into our bloodstream quickly and it is the only thyroid hormone that it is required by our body to function properly, i.e. heart, brain etc. but it has to saturate our T3 receptor cells first and then its work begins and lasts between 1 to 3 days.

This is a link with information.

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5mcg of T3 is equal, in effect, to around 15mcg of levo. You usually take 75mcg of levo daily and if you reduce it to 50mcg today and add 5mg of T3 your dose will be 65mcg of thyroid hormones, less than you take with levo alone. If you take 50mcg of T4 today plus 10mcg of T3 your daily dose would be 80mcg approx of thyroid hormones.


Minus, I'd try 50/75mcg Levothyroxine alternate days plus 5mcg T3. The combined dose will be equivalent to 77.25mcg Levothyroxine. FT4 is likely to drop a couple of points and FT3 should increase slightly. It's highly unlikely that 5mcg T3 will raise FT3 anywhere near the top of range, let alone over.


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.

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Clutter, I took 50mg of Levi and 5mcg of t3 today. Felt a bit fuzzy headed or dizzy on and off throughout the day.but OK enough to have brisk walk and day out with family. I suppose it takes time for body to get used to t3, my body temp was 36.7 c in morning blood pressure was 107 over 77 pulse 72 which is Lowe than when on t4 only therapy. Wander if I have reverse t3 clearing slowly from my body?


A lot of people get increased blood pressure when taking medication for thyroid. One can go with the other. I had it and when I stopped taking the medication the blood pressure returned to it's former low and safe numbers.


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