Adding T3 to T4 for the first time: I posted here... - Thyroid UK

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Adding T3 to T4 for the first time

Chrissie78 profile image
12 Replies

I posted here a few weeks back after I had some private blood tests done and shared the results with my GP.

I ordered some T3 online, and it arrived today! I'm nervous to try it without being directly prescribed, but I'm certain that just increasing my T4 (levothyroxine) wouldn't help (which is what my GP suggested) as I'm already out of the top end of fT4 range. My TSH could do with being lower, so I wonder if I do increase the T4 as per my GP advice, or just try the T3.

I'm on 150mcg levothyroxine Daily and take 1x210mg ferrous fumarate bd. And added 5000IU vitamin D daily after I got these test results. I'm also taking a selenium supplement but I can't remember the dose, and I don't have it nearby.

I read it is suggested to reduce T4 by 50mcg and add 10mcg T3 replacement, but I wonder as my TSH is a bit higher than I would like, I should stay at 150mcg T4 and just add the T3. I have 25mcg T3 tablets - should I half/quarter them and see how I go? Any advice is greatly appreciated.

30Jun2017 bloods for info:


FREE THYROXINE *22.1 pmol/L (12-22)

TOTAL THYROXINE(T4) 135.7 nmol/L (59-154)

FREE T3 4.45 pmol/L (3.10-6.80)

REVERSE T3 *34 ng/dL (10-24)

T3 RATIO *8.52 (15.01-75.00)

THYROGLOBULIN ANTIBODY *513.400 IU/mL (0.00 - 115.00 )


VITAMIN B12 395.6 pmol/L ( 140.00 - 724.00 )

FOLATE (SERUM) 11.02 ug/L 25 (2.91-50.00)

OH VITAMIN D 50.27 nmol/L (50.00-200.00)

Interestingly, my ferritin came back as 143.8 when it was 55 only 2 weeks earlier... the only thing I did was cut out dairy and gluten in case it was slowing iron absorption.... I am going to retest again in a couple of months.

Thanks xx

12 Replies
SeasideSusie profile image

Chrissie78 You definitely shouldn't increase Levo as your GP suggests, that would put you in danger of creating more reverse T3 and you already have enough!

My suggestion is to reduce Levo by 25mcg and add in one quarter of a T3 tablet - 6.25mcg. T3 is approximately 3-4 x the strength of Levo, so 6.25mcg T3 is roughly equivalent to 18.75-25mcg Levo. That should bring your FT4 down a bit. Stay at that for two weeks then add in another 6.25mcg T3. I would then stay at that for 6 weeks and retest. Some people only need a bit of T3, others need plenty more. Some need lots of tweaking with Levo and T3. It's trial and error.

With a reverse T3 that high you might find you need more T3 and less Levo to bring it down. I'm still tweaking after 18 months and haven't found the perfect place yet!

misfitjones profile image
misfitjones in reply to SeasideSusie

Hi Chrissie and sorry to jump on the band wagon but I just posted an almost identical question. can I ask seasidesusie I did the first add of 6.25mcg of t3 and lowered 25mcg t4 13 days ago and after reading this looking at adding the 2nd dose 6.25mcg t4 tommorow. Do I lower my t4 by another 25mcg. sorry if it is obvious but I don't want to mess this up.... thank you for any advice x

SlowDragon profile image

Personally I started on 1/8th tablet (yes it was a speck of dust, but still very noticeable) twice a day for first 4-5 days, plus dropped T4 buy 12.5mcg. (From 125 to 112.5mcg)

Then increased to 1/4 tablet twice a day and reduced T4 from 112 to 100mcg. This was done under endo guidance. After two months increased to 3 x 1/4 tablet. That was uni-Pharma 25mcg tablet

Now changed to Mercury Pharma (doesn't seem quite as strong) 20mcg tablet and divided dose of 1/2 tablet on waking and 1/4 tablet at noon and 6pm approx. I take T4 at bedtime.

I have Hashimoto's and DIO2 gene variation

I use a craft scalpel knife to cut tablets

Mouldyoledoll profile image
Mouldyoledoll in reply to SlowDragon

How do you find out you have the DIO2 gene? And what does it mean? I have hashis

SlowDragon profile image
SlowDragonAdministrator in reply to Mouldyoledoll

It's a saliva test - costs £60 plus £60 counselling (all DNA tests have to include counselling)

Test can be booked here

Relatively new research. It is increasingly recognised as genetic reason why addition of T3 is needed

You can have single variation from one parent (heterozygous) or from both parents (homozygous)

I have heterozygous variation and have found significant benefit from additional T3, but only once I was strictly gluten free and all vitamins at top levels.

Mouldyoledoll profile image
Mouldyoledoll in reply to SlowDragon

Do gps or Endo's take any notice of this tho?

SlowDragon profile image
SlowDragonAdministrator in reply to Mouldyoledoll

Yes mine does.

Was extremely interested.

I started on T3 before I did DNA test.

Chrissie78 profile image
Chrissie78 in reply to SlowDragon

That is really interesting, thanks. I might look into it further.

I'm trying hard to be gluten free, but as I dont have celiac (GP tested, but I don't eat much bread/pasta, so wonder it was a false negative) or any major gut symptoms other than hoping it helps my thyroid conversions and hypo symptoms, I don't feel like I'm taking it seriously! If I had evidence to base it on, I might feel like I have reason to do it properly.

Lots to think about! Day 2 of 6.25mcg T3. Don't feel much different TBH!

C xx

SlowDragon profile image
SlowDragonAdministrator in reply to Chrissie78

As you have Hashimoto's you really need to try 100% strictly gluten free for at least a month - 6 months would be better. See if antibodies fall.

You don't have to have any gut symptoms and it's not coeliac. No test for gluten intolerance you just have to try it.

Chrissie78 profile image

Thanks SlowDragon,

Will lowering my antibodies help with symptoms? The main one concerning me is hair loss. But also have brain fog, lack or energy, dry skin, cold hands and feet.

And of course, difficulty in losing weight. I hate looking like I eat kebabs and chips every day with chocolate every hour in between, when in fact I follow a health calorie controlled diet and exercise (run and HIIT) 4x a week. Grrrrr.

I was diagnosed 10 years ago, so assumed my natural thyroid function has packed in completely by now! Will lowering antibodies at this point help my natural function? And therefore reduce my need for replacement medications?

So many questions!

Thanks again Cx

humanbean profile image

Interestingly, my ferritin came back as 143.8 when it was 55 only 2 weeks earlier... the only thing I did was cut out dairy and gluten in case it was slowing iron absorption.... I am going to retest again in a couple of months.

What did your doctor say about your dramatically raised ferritin, if anything?

For doing a check on just your iron you might want to consider this test :

Chrissie78 profile image

Hi Humanbean,

My GP did not mention the ferritin. I didn't ask specifically about it, I was more concerned about my RT3. I do wonder if it was a difference between labs, but surely that couldn't triple the result!? They were the same units as far as I could see.

I have an appointment tomorrow, so will see what she says then. I have a long appointment with her as I'm getting a coil changed (sorry if TMI!) so if I'm up to having a chat whilst I'm in the stirrups, I might take the opportunity!!

The coil change is from copper IUD to Mirena in the hope it lessens my periods, and therefore helps ferritin levels by reducing blood loss. Gotta give it a go. She seemed to be helpful in that regard. But if it is an absorption issue drastically improved by going dairy/gluten free I'm not sure if she will have any more knowledge than me.

Might still ask about a referral to an endocrinologist with my new found Thryroid antibody status.

Thanks for the replies, it is really useful.


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