T4 and T3: My endo is trying me on a combination... - Thyroid UK

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T4 and T3

SusanAR profile image
31 Replies

My endo is trying me on a combination of T4 and T3.

I have to reduce my Levo from 125mcg to 100mcg and tomorrow I collect a prescription for 20mcg of T3.

I asked my GP how to take the T3 - do I build it up / split the dose? He said just to start taking the 20mcg in the mornings as soon as I get it.

Anyone’s thoughts would be appreciated!

I’m still on 125mcg Levo which I will reduce as soon as I get the T3.

Thank you 😊

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SusanAR profile image
SusanAR
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31 Replies
Jazzw profile image
Jazzw

Just checked your last post to see if you’d posted all your thyroid results but couldn’t see them. First of all - well done! After your post about the disastrous visit to the woman who drew a butterfly, getting T3 seems quite a result!

But what were your thyroid results? Just wanting to see whether you should reduce your Levo at all or whether you simply need to add the T3.

For what it’s worth, I certainly wouldn’t start with 20mcg liothyronine all in one go. Think I’d go slower than that and add 5mcg each week - build up slowly!

SusanAR profile image
SusanAR in reply toJazzw

Thank you for your reply!

TSH 0.01 (0.2-4.5) this was 4.2 last check

FT4 16 (9-21) this was 12 last time

He wanted to get my FT4 to the top of the range but it only got to 16 in the 3 months.

I couldn’t believe it. I didn’t even ask for it. He phoned me the next day after my appointment and told me he wanted to try this. He’s great. It’s just a shame I didn’t get to see him on the day but at least I know he’s keeping an eye on things.

Jazzw profile image
Jazzw in reply toSusanAR

Yes, great result. :) Such a pity he didn’t think to check FT3 though. :(

Well, your FT4 levels become less important when you take T3. It becomes all about your FT3 levels and getting those nearer the top of the range (you’ll find most likely that your FT4 levels will drop, even if you stay on the same amount of levothyroxine. I’ve no idea why that happens but I’m on a good amount of NDT and my FT4 levels are usually really low in range).

I think what I’d try is sticking to 125 μg and adding 5mcg of lio each day this week. Then upping to 10mcg lio next week (keeping at 125 μg of Levo). Then go up to 15mcg lio the next week but dropping the Levo to 100mcg then up to 20mcg the next.

That might all be a bit overcautious - my other half got started straight on 10mcg of lio and was fine - but sometimes people find it too much to start with because it’s the active form of thyroid hormone.

I’m sure others will chip in. :) But an FT3 result is gonna be needed at some point, so make sure it’s on your next set of bloods!

SusanAR profile image
SusanAR in reply toJazzw

Great thanks. I’ll definitely do it slowly.

I got 56 tablets - I was really surprised with that too!

I’ll definitely ask for T3 to be checked next time. Surely when that’s what you’re taking it would be stupid not to test it...... but you never know!!

Jazzw profile image
Jazzw in reply toSusanAR

You’d think, wouldn’t you? But when my other half was taking it, we had to remind the Endo every time that he needed to write it on the form...

I like SeasideSusie ’s advice better than mine - go with that. :)

SusanAR profile image
SusanAR in reply toJazzw

It seems that everyone is different with the way they cope with it. I might wait until the weekend so I don’t feel dodgy at work!

Jazzw profile image
Jazzw in reply toSusanAR

Good idea. Most likely you’ll be absolutely fine - and hopefully feel lots better!

shaws profile image
shawsAdministrator in reply toSusanAR

Hang on to this doctor :) He seems to consider the patient's symptoms first and foremost.

SusanAR profile image
SusanAR in reply toshaws

He’s really good. I said I wanted it noted that I still didn’t feel 100% and he’s acting on that. I just hope I actually see him next time.

SeasideSusie profile image
SeasideSusieRemembering

SusanAR

I asked my GP how to take the T3 - do I build it up / split the dose? He said just to start taking the 20mcg in the mornings as soon as I get it.

Oh for goodness sake! And why on earth has your endo not given you instructions on how to introduce T3? They really are stupid. How do they expect you to know.

Are these the results (taken from previous post) that the endo has based his decision on?

TSH 0.01 (0.2-4.5)

FT4 16 (9-21)

So where is the FT3 that the endo needs to make the decision to trial T3?

Well, with your FT4 just 58% through it's range, there's no way you need to lower your Levo to 100mcg. You can just start adding T3 to 125mcg.

Start by adding 1/4 of a tablet (5mcg) in the morning, take that for 2 weeks and see how you are.

If no adverse reaction, add a second 1/4 of a tablet (total 10mcg), you may want to add that in the afternoon. Stay on 10mcg for 2 weeks and see how you go.

Personally I would stay on that for 6 weeks and retest - TSH, FT4 and FT3. Absolutely essential to test FT3.

See what your levels are like and how you feel.

If necessary go up to 15mcg, 10mcg morning, 5mcg afternoon if you're still splitting the dose. Give it 6 weeks, retest.

If necessary go up to the full 20mcg, 10mcg morning, 10mcg afternoon if you're still splitting the dose. Give it 6 weeks, retest.

Don't rush it, increasing slowly and gradually is best so that our bodies get used to the extra hormone.

I think if you lower your Levo you will feel worse. You can always decide on what to do about that when you see your levels on retesting, there's a lot of tweaking involved when taking a combination of Levo and T3.

Same rules apply for T3 as Levo - take on an empty stomach, one hour before or two hours after food, away from other medication and supplements, etc.

When retesting, leave off Levo for 24 hours before the blood draw, and leave off T3 for 12 hours. Essential to get the timing right for T3 because it peaks 2.5 hours after ingestion and there is none left in the blood after 12 hours.

SusanAR profile image
SusanAR

Brilliant thanks! That’s exactly what I thought from reading other posts on here.

Never had my T3 tested but I’ll be asking for it in 6 weeks when I’ve to go for the next blood test. I’m hoping he’s just trying to make me feel better and doesn’t want to lower my TSH any more by adding more T4. It’s definitely worth a try.

He’s upped my vitamin D too which was a surprise!

Thanks for your advice, it’s appreciated!

greygoose profile image
greygoose in reply toSusanAR

Well, he's backing a loser, there. Adding T3 to your levo is definitely going to make your TSH go lower. Don't they know anything?

MaisieGray profile image
MaisieGray

When I was first prescribed T3 I was taking 125 mcg Levo. I was advised to simply add my 20 mcg T3 to my existing 125 mcg T4 and that's what I did with absolutely no problem whatsoever. That was 10 yrs ago. A few months ago I restarted T3 having had it withdrawn last year and being without it for a period; and again I simply started taking the same 20 mcg dose with no tapering and no problem. More recently my Endo asked me to increase my dose to 2 x 20 mcg and again, I added in the full second tablet, no problem. The advice here tends to be more cautionary of course, but I can only describe my own experience and say honestly I've not had a problem.

SusanAR profile image
SusanAR in reply toMaisieGray

Thank you. It’s good to know people have different experiences.

I have to admit I’m a bit scared of it at the moment! I’ve never taken anything fast acting before. I’m definitely keen to try it though. Hopefully it’ll make a difference to me!

Aurealis profile image
Aurealis in reply toSusanAR

I also started on 20mcg split across two doses. I certainly improved quickly which I was grateful for, as I was very poorly at the beginning. However it was trickier down the line to get it stable. The problem is that if you have to reduce your Levo it takes some time to reduce. I think it’s best to keep Levo stable and learn how introducing T3 and adjusting it affects you. So introducing at a small dose has some advantages. However you may find that once you introduce T3 in the morning you slump in the afternoon without a second dose 8 hours after the first. So I’d say 5mcg in the morning but also if you have to, 5mcg in afternoon. There’s no need to avoid taking it near food or drinks. A third dose 8 hours later may improve sleep later on if you need it. If doses are not of equal size, the first dose of the day should be biggest. This advice is based on my experience and what I’ve read over the years.

SusanAR profile image
SusanAR in reply toAurealis

I’m going to try 5mcg in the morning and I’ll take another 5mcg to work just in case. I was going to leave it until the weekend but I may as well get started!

Thank you.

Judithdalston profile image
Judithdalston

You'll find almost as many answers to your queries as there are hypothyroid sufferers taking T4/T3 combo...you'll have to experiment and find out what suits you. However I found taking 1/8 th of a 25 mcg pill as a starter dose immediately had an affect..loosening up my hips and lessening pain so I could walk more easily, but I did have palpitations and high heart rate at times, which went completely by the time I got to the full 25 mcg dose daily a month or so later. I tried taking half the dose with my T4 at bedtime, middle of the night and early morning, and took another half 4-5.30 pm ....but now upto 37.5 mcg I just take the whole with my levothyroxin early morning. I found taking other vitamins/ minerals especially iron, along with eating, and other meds meant it was difficult to keep everything separated with appropriate 2 plus hours apart, so night time dosage is relatively easy. With regard to whether to reduce T4 dosage- you will find numerous e.g.s advising cutting T4 down by 25 mcg for every 10 mcg of T3 added...but this 'formula' was completely wrong for me...I cut my levo down to 75 mcg( from 125 mcg) while adding 25 mcg T3 to find not only did my TSH go down nearly 10 fold, FT4 reduced, but so did my FT3. I had to add my levo back again; now amazed that my T3 is now as high as 37.5 mcg (admittedly not blood tested yet). My Bp is ok, but basal body temperature has only ever risen by 0.3C, and still reads under 36C regularly. Just advise patience, add no more than 1/4 pill till you are sure your body is coping.... Good luck.

SusanAR profile image
SusanAR in reply toJudithdalston

Thank you.

I was worried it would keep me awake if I took it at bedtime. At the moment I can fall asleep any time anywhere though!

I’m hoping it makes me warmer. At the moment I’m wearing 2 pairs of thermal leggings under my trousers and a thermal vest, a normal vest, a jumper, a cardigan and a coat!

Judithdalston profile image
Judithdalston in reply toSusanAR

Yes I can sympathise with that, although my basal temp.has not changed much I don't feel as cold in my core, tho have resorted to thickest socks I can find in this cold spot. You can experiment with timings/ dosing even if same dose over 24 hour period.

Susieibbo301 profile image
Susieibbo301

My endo said to cut T3 into 4 and take one am before food and one 4-6 hours later and then another later. All away from food. I think it is better splitting doses to start with but I believe that then some people take it all in one. I bought a virility pill processor from the chemist which is brilliant and stores as well as crushes. Best of luck!

Marz profile image
Marz in reply toSusieibbo301

A virility pill processor - the mind boggles. 😊😊

Susieibbo301 profile image
Susieibbo301 in reply toMarz

So sorry predictive texting - ‘Vitality’ !!

SusanAR profile image
SusanAR in reply toSusieibbo301

Thank you. I still have my pill cutter I used for my painkillers when I had my thyroid removed so I’m going to get it ready for the next few days.

Susieibbo301 profile image
Susieibbo301

That is with a 20mg pill as well.

I started taking 20mcg Liothyronine all in one dose in the morning and reduced levothyroxine by 25mcg as advised by Endo. Felt a bit dizzy at first so started taking it at night with Levo. After a few weeks or so reverted back to morning dose as I didn’t think I was getting full benefit and didn’t get any dizziness. Read advice on this forum to introduce dose slowly but it was too late by then!

SusanAR profile image
SusanAR in reply to

Thank you. I might take it once I get to work in case I get dizzy on the drive!

SusanAR profile image
SusanAR

Thank you to everyone for the replies and advice. I really appreciate it.

I was feeling quite nervous about starting the T3 but now I’m feeling very prepared and looking forward to seeing an improvement.

momindenver profile image
momindenver

I'm still experimenting with T3 dosing. I feel best if I divide the total day's dose up and take 5mg at a time, about 5-6 x/day. I read that one single dose peaks at 4 h and is out of the system by 19 h, although I suppose it varies in patients. I talked with a compounding pharmacist (in the US) and his formulation peaks at 9 h, allowing 2-3x/d dosing. Physiologically normal is to have a fairly constant level of T3 in the bloodstream, so I think that is where most people will feel the best. Incidentally, the compounded medicine is quite a bit cheaper than the liothyronine tabs (generic Cytomel) that the endocrinologist prescribed!

Stourie profile image
Stourie in reply tomomindenver

I take all of my t3 at bedtime every evening and manage to sleep almost every night. Jo xx

SusanAR profile image
SusanAR in reply toStourie

Thank you that’s good to know. I’m so used to sleeping at least 9 hours straight through that I worry I wouldn’t cope on less sleep. But if the T3 gives me more energy maybe I won’t need as much sleep. Hopefully anyway.

SusanAR profile image
SusanAR in reply tomomindenver

Thank you. I’ll definitely try splitting it. I was going to start today but I forgot to take it 😂. I’ll start tomorrow.

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