T3 never tested?


I've recently been diagnosed hypothyroid after having numerous tests over the years. I just wondered why I've never had t3 tested? Is this not standard practice in the NHS. I've been taking levothyroxine for 4 weeks and have another appointment with the endocrinologist tomorrow, should I mention t3? Surely he must know about this?


7 Replies

  • They only test T3 if you take T3 medication or if taking levothyroxine doesn't work (in about 1 in 10 people) and they want to find out why.

    They only measure your TSH and FT4 for most people.

  • Thanks Claudiasmum :-)

  • If your TSH is within 'normal' sometimes that's all they do. Sometimes they do T4. They rarely do a T3 test unless TSH or T4 are 'out'. Even if doctors request a T3 it isn't always done. I think it may be more expensive but not much help to us if our T3 is 'below' and we are feeling awful.

  • Hi i wondered about this also,my endo will only test tsh but gp will do tsh and t4 and i have had my thyroid removed and am taking levo only have asked numerous times for t3 to be tested but am told i dont need it !

  • Penguin most labs don't test FT3 unless TSH is suppressed <0.03. You can order private tests from Blue Horizon and Genova but I don't think it is worth it until you have been optimally dosed for 2/3 months. As you've only been taking Levothyroxine for 4 weeks you may need your dose increased after your next blood test and are unlikely to be optimally medicated yet and FT3 takes longer to respond to thyroid replacement than TSH and FT4.


  • Thanks clutter that's helpful. I'm still feeling quite tired and cold and my hair's been shedding massively so I'm hoping it will kick in soon. How long should it be before people generally notice a difference? I had tsh and t4 blood tests yesterday so I'll hopefully get the results tomorrow....

  • Penguin, you'd normally expect to notice a little improvement within 14 days of starting Levothyroxine but as some symptoms won't go until you are optimally medicated it is a slow progress and can take months :(

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