If I choose to start on T3 supplementation, how do I calibrate this with my present 125mcg of levo?

Many thanks to those that responded to my last question re -adding in T3. So if I start on T3, do I cut back on my Levo ( presently 125mcg) or is T3 a "complementary" extra that works with levo , and so can be taken with my usual dose? Sorry to sound ignorant, but don't want to take chances with self medicating! ( Also thanks to those who sent details of where to get it - I had no idea I can get it through <removed in line with community guidelines>)

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  • Liothyronine (T3) is a prescription only medicine, are you sure you've bought T3 on (unnamed website) ? It's more likely you've bought a thyroid supplement. It is important you check exactly what you have bought because if you reduce your Levothyroxine (T4) you could end up very under medicated.

    T3 is 3 x stronger than T4 ie 25mcg T3 is equivalent to 75mcg T4. T3 is usually split into two or more daily doses with the first dose being taken with Levothyroxine.

    If you have bought thyroid supplement take it two hours away from Levothyroxine in case any of the ingredients affect absorption.

  • No, sorry - I bought it on (unnamed website), after getting info about suppliers from the site - it came from Turkey, I think!

  • Is is Tiromel?

  • Yes, I was surprised to see them selling it. It is the real deal, I took it myself last year, so take it slowly :)

  • Did you find it stronger or the same as the NHS T3 Clutter? I find Cynomel the strongest and purest, it is the one I think that Dr Lowe advised on.

  • I've not noticed any difference, Marmaris, other than the fact Tiromel is 25mcg and Liothyronine 20mcg.

  • Hi Clutter I have been taking my Levo at night for some time now. I see you mention the 1st dose to be taken with Levo in the morning (ie T3) does it work better that way? So if I am now taking 50mcgs of Levo (reduced down recently from 100mcgs by Endo) and now upped T3 from 20mcgs to 30mcgs what it the total I will be taking now with the guidelines you are giving? Its just that some say T3 is 4 or 5 times stronger and you are saying 3 times stronger. It all gets confusing, sorry was just wanting to clarify. Thanks.

  • Marmaris, Levo and T3 should be taken when it suits you. I used to take all my T4+T3 at night but it stopped me having milky drinks and biscuits so I switched to morning. Endo advsed me to split dose T3 so I take 100mcg T4 with 20mcg T3 in the morning and 20mcg T3 12 hours later (or when I remember). If I was busy and hit a slump I'd take the 2nd dose earlier if I felt I needed it.

    I work on the 3:1 ratio so 30mcg T3 is equivalent to 90mcg T4 and you are now taking the equivalent of 140mcg T4. ncbi.nlm.nih.gov/pubmed/204...

  • Thanks for that Clutter so my T3 30mcgs = 90mcgs plus I am taking 50mcgs T4 = 140mcgs. Thanks for that Clutter

  • Two points.

    1. The T3 will accumulate quicker than the T4 will reduce, due to the different half-lives so I would reduce the Levo to 100 mcg and after 3 days take 5 mcg T3 and after another 3 days up the T3 to 5 mcg twice daily. 5 mcg is a quarter tablet, assuming you have UK liothyronine.

    2. I'm sure liothyronine is 3x as potent as levothyroxine. I believe the 4x or 5x figures came from old research on the relative potency of fT3 and fT4 in the blood. The tablets have different half lives and absorbancy. However, earlier today I sent an e-mail to the BNF (the journal that describes drugs for doctors) asking them to reconsider their advice on the relative equivalence of the two drugs (4x - 5x). I guess it will take a few months for a response, if they give one. Once I have received a response I will forward it to the owners of the major thyroid support groups.


  • This is interesting. Thanks :) I found that I had to replace my 125mcg levo with 100mcg t3. Most strange! I have to take t3 only as any amount of t4 appears to make me very unwell.

  • I agree, but my Endo wanted me to drop Levo and upped T3.

  • Liz,

    Assuming the T4 dose is optimal to start with then reducing T4 to add an equivalent amount of T3 is fine. The problem is when someone is under medicated on T4, the dose reduced and T3 added in. The person is still undermedicated and can't feel the benefit of T3.

  • I really dont know what to do then. My tsh is alway suppressed on 100mcgs which is 0.07. I think that the Endo is afraid of over medication by adding more T3. It really is swings and roundabouts.

  • Why not see how you do on 50mcg T4 + 30mcg T3? Resolving your symptoms is the important thing not the poxy TSH test. Long time suppressed TSH may increase the chance of osteoporosis but bone density can be monitored with DEXA scans every two years and if it's low a once a week dose of Alendronic Acid or something similar.

  • Wow thank you for that information Clutter. I have had two bones scans over the years and the Endo said they are fine, due another one next year. With the cervical spondylosis that I have she has said it is the cartilage in between that is causing that and not the bones. I said I was taking HRT for that (now off it), she said that it was not necessary for the bones and that I could have an injection once a year for that????? I am trying the 50mcg of T4 now (last two days) and 30mcgs of T3 because my ths has been suppressed for a long time now, (that was on just T4 alone). Can you get the Alendronic Acid on prescription? Is it for bone strength? Many thanks for your info greatly appreciated I have learnt so much from this site.

  • Yes AA is on prescription but a lot of people think it causes more problems than it solves but there are alternatives like strontium citrate which may not be as problematic but may also cause issues.

    My sister takes AA and hasn't had any apparent adverse effects but I'm wary of anything which might rock my boat and set me back now I'm recovering and need to do my homework before I see my endo in Sept.

    If you check out Londinium, Framboise and Cinnamon-Girl's posts they have researched a lot of stuff on osteoporosis and treatments.

  • Guys, please make sure you are not naming places where you can obtain t3 without prescription.

    22.Do not post advertisements, links or information of any sort whatsoever, on where or how to obtain UK prescription only medications without prescription.

    For full posting guidelines


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