T4 / T3 Combo: Can any folk who successfully take... - Thyroid UK

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T4 / T3 Combo


Can any folk who successfully take a T4/T3 advise on whether it is best to reduce T4 dosage (Levo) when starting added T3 (Tiromel). I am precribed Levo but going to self medicate T3 because I am not converting T4 to T3 too well and do not feel great on T4 only. I am on 100mcg and bought 25mcg of T3. Should I be cutting down to 75mcg Levo if adding the T3?

I don't want to over medicate or raise my T4 levels to higher than normal range ( it is getting near to that on T4 only now). My GP won't prescribe T3 or support me in taking it myself. I have read numerous success stories from folk who take a combo, I thought it worth trying.

17 Replies

Hi, twin mommy, all I can tell you is my experience; it might not be the same for you, so a good guide is to take it slowly and gradually when making changes. I was on 100mcg T4, not doing well (weight gain, constipation, hair loss, fatigue etc; you know, the usual). A good doc I used to have (now retired) prescribed adding 20 mcg T3 as an experiment but to start off with 10mcg for two days, then for the next two days 15 mcg, then if all is still well, up to 20; all was well and after a week we then took that up to 25 (and personally I think I could use more, but I have no doctor at the moment so we'll see). This was done using multiples of the 5 mcg pills. I don't know if the higher dose pills could be split so you could start at a half dose for a few days and raise gradually. What he told me to watch out for was heart pounding, sweating, feeling jittery like bad caffeine. I got none of that; felt nothing at 10, slightly more alive at 15 and 20, and think maybe more is in order to bring me back to actual life. Again, this is only one person's experience so you really have to listen to your own body and see how the medicine affects you. Good luck!

MapleMoose in reply to acoldiron

Thank you so much. Did you have to cut back on your T4 dose or just kept it the same? Also did the T3 help with weight gain? I gave read that for some they gained weight on T3... A big no, no for me.

Sorry, twinmommy, the main point of your question: no, the doc did not reduce the T4 during this addition.

MapleMoose in reply to acoldiron

Oops replied before your ammended message, thanks :)

acoldiron in reply to acoldiron

Ps-. No help yet with weight!


If you post your recent thyroid results and ranges members will advise whether Levothyroxine dose needs reducing when you add T3.

MapleMoose in reply to Clutter

Thanks, my last results from around 3 wks ago are:

T3...4.3pmol/L (norm range:- 4.0-7.0)

T4...23pmol/L (norm range:-


TSH....0.03mU/L (norm range:-


Higher T4 and lower T3!??

Clutter in reply to MapleMoose


I don't think you need to reduce Levothyroxine dose. I would add a quarter tablet (6.25mcg) to your current Levothyroxine dose to see how well you tolerate it. If necessary, increase to 12.5mcg taking the second 6.25mcg dose at bedtime. Hold at 12.5mcg for 6-8 weeks and recheck thyroid levels, particularly FT3, before raising further.

MapleMoose in reply to Clutter

Thank you, appreciate it!!

Hi twinmommy

I'm stable on a T3/T4 combo. It took a while and I was quite ill first. I was previously on 100mcg of levothryoxine and not doing well at all. The doctors reduced my levo to 50mcg and added in 20mcg of t3 (taken twice daily) I was great for about 4 weeks while the high dose of levo was in my system, then felt increasingly ill as it reduced, in fact, that was the sickest I've ever felt before! The first blood tests showed that my free T4 was on the floor but that the T3 levels were good, so they very slowly increased my levothyroxine back to 100mcg. And that's where I am just now, I reckon I was underdosed on levothyroxine. Once they got the levels right, I felt fab, so much so I'm back to hillwalking every weekend, can weight train and brain fog is totally gone. It's definitely worth sticking with, although hard to get the dose right.

Best of luck xxx

MapleMoose in reply to helen_m

Thank you for sharing your story, appreciate it!

Did you have any issues with getting Tiromel ? A family member just tried to source me some today in Turkey and they're saying 2 weeks to order in 😐

monica123 in reply to TimD250172

I got tiromel past week. Went to one chemist and they were having trouble getting it. Went to the next chemist and got 4 boxes no problem. Just get them to keep.popping into different chemists. Hope they manage to get you some.

TimD250172 in reply to monica123

Thanks Monica123, they're in Marmaris and have tried pretty much all the pharmacies 🙁

It did take a few weeks but I bought it ages ago and didn't take it until I could convince a GP to test my T3 (had to be sneaky and see a locum who thankfully agreed). Just started. I need to get more if it agrees with me because I only purchased a small quantity as a test. Best of luck getting it. To be honest I can't remember online company I got it from. Is Tiromel good for you? I got that only because I coukdn't get Cytomel in a small batch.

Hi, I'm like you. I thought I'd give it a try to see if I can bring my T4 down as over range and my T3 is about 3/4 so thought I'd experiment a bit.

All the best!! I'm hoping it helps me. You can buy Tiromel online from Fitness sights, mostly American, in smaller quantities. Can't believe people mess with this stuff for vanity and not health, very dangerous.. At least it means it's accessible to those of us with unhelpful docs and no endo support.

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