How much t3 should I take- I’m on 75mg Levothyr... - Thyroid UK

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How much t3 should I take- I’m on 75mg Levothyroxine

Hello ,

I’m on 75mg levothyroxine how much t3 should I take and when also what brand should I buy?

Thank you 🙏🏽 xx

7 Replies


You need to have current results for TSH, FT4 and FT3 before anyone can say how much T3 you should take and whether you should lower your dose of Levo.

As for brand, it's not easy to get T3 at the moment, so it's a case of try whatever you can get and see how you get on. Different brands suit different people, just like Levo or NDT.

And you need to test Vit D, B12, Folate and Ferritin and have optimal levels before introducing T3.


Before considering adding T3 it's essential to get FULL Thyroid and vitamin testing

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also extremely important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially if Thyroid antibodies are raised

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and fasting. Last Levothyroxine dose should be 24 hours prior to test, (taking delayed dose immediately after blood draw). This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

Is this how you do your tests?

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or all vitamins

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random

If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease).

About 90% of all hypothyroidism in Uk is due to Hashimoto's.

Low vitamins are especially common with Hashimoto's. Food intolerances are very common too, especially gluten. So it's important to get TPO and TG thyroid antibodies tested at least once .

Link about thyroid blood tests

Link about antibodies and Hashimoto's

List of hypothyroid symptoms

Come back with new post once you have results and ranges and members can advise on next steps


From reading your last post it would seem your FT4 is good - so you do need to know if it converts into the Active T3 - hence the need for a test. I read that an earlier FT3 test result was low. This could be due to low levels of B12 - Folate - Ferritin and VitD - they need to be optimal for the T4 you are taking to convert into T3 :-) So follow the advice before introducing T3 - if the foundations are not in place you are setting yourself up for more problems ...


Hi I had a full panel in Nov and getting another blood test in the next few days. my recent results were as follows

- Ft3=3.3 (low), iron=47, Ft4=22.4(high), Vit D=60 (low should be higher), B12 was high because i was on supplments which i have stopped now.


When you have your new results, post them on the forum and include the reference ranges. Ranges are important because they vary from lab to lab and we can only interpret your tests if we have the ranges that came with them. Members will then be able to comment.

Hopefully you've been supplementing to improve your Vit D level, so it's important to test that now as well. Also, ferritin, folate and B12 current levels are needed.


ok thank you


yes i have suplementing Vit D - I dont think the GP has put ferritin, folate on list . thanks again


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