Thyroid UK
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Confused re T3 Dosage

Good Morning Everyone,

Am after some advice please. At the end of September I was allowed a 3 month trial of T3 to be added to T4 as I wasn't feeling any better on T4 alone. Prior to starting on T3, I was alternating between 75mcg T4 one day, and 100 the next. The endo suggested dropping to 50mcg t4 one day and 75mcg the next and adding in 5mcg T3 daily, which I started on 24 Sept. Initially this did help and I felt a lot better, but after 2-3 weeks I felt rotten again with the aches and pains and excruciating headaches returning. On advice I received here, from 12 Oct I upped this to 75mcg T4 each day and 5mcg T3. I felt better on this but felt there was still room for improvement. I had further bloods done 12 Nov as follows.

Results 12 Nov 16 ( older results listed further below)

FT4 18.92 pmol/L (normal range 12-22)

FT3 5.3 pmol/L (normal range 3.1-6.8)

TSH 0.0112 mU/L (normal range 0.27 - 4.2)

When I saw the endo end of November he seemed irritated that I had upped the levo each day to 75mcg, as opposed to the alternate 50 - 75 dosage he suggested.

I said that although I was feeling much better , I still have low energy but more than I had before adding the T3.I felt there was room for improvement and asked if I could increase the T3. He said he wouldn't prescribe an increase of t3 as he didn't want me going over active. I was wanting to either reduce t4 or add further t3 to the mix. Either way I just feel the improvement felt on a small amount of t3 suggests this is helping me more than the t4 did.

He agreed a further 3 month trial of 5mcg daily to be added to 75mcg T4 and follow up bloods and apt with him in 3 months.

For the last 3 weeks the aches , pains and fatigue have started to return and I just feel I am not firing on all cylinders.

Could you advise if my results would suggest a small increase of T3 would be worth trying.

Thank you :)

Older Results


FT4 26.47 pmol/L (normal range 12-22)

Ft3 5.9 pmol/L (normal range 3.1 - 6.8)

TSH 0.027 mU/L (normal range 0.27 - 4.2

May 2016 Vitamin D =77 ( range 50-250)

11 July 2016 Short Synacthen Test

The basal level needs to be above 100, 30 min sample needs to be above 500 nmol/l with an increment of at least 200 nmol/1

Basal 468

30 Mins 815

60 mins 905

LH 11.4 U/L

follicular 2.4 - 12.6

Ovulation 14.0 - 95.6

Luteal 1.0-11.4

Post Men 26 - 135

FSH 21.1 U/L

follicular 3.5 - 12.5

ovulation 4.7 - 21.5

Luteal 1.7 - 7.7

Post Men 26 - 135

B12 723* ng/L (199-663)

Folate (serum) 13.9 ug/L (4.6-18.7)


WBC 4.9 X 10^9/l (4.0-10.0)

RBC 4.56 X 10^12/l (3.8-4.8)

HAEMOGLOBIN 154* g/l (120-150)

HCT 0.44 ratio (0.36 - 0.46)

MCV 97.0 fl (83 - 101)

MCH 33.8* pg (27.0 - 32.0)

MCHC 347* g/L (315-345)

RDW 12.5 (11.0-14.0)

Platelets 222 X10^9/L (150-410)


Neutrophils (abs) 2.5 10^9/L (2.0-7.0)

Lymphocytes (abs) 1.5 10^9/L (1.0-3.0)

Monocytes (abs) 0.5 10^9/L (0.2 - 1.0)

Eosinophils (abs) 0.30 10^9/L (0.02 - 0.50)

Basophils (abs) 0.11* 10^9/L (0.02 - 0.10)

Erythrocyte sedimentation rate 13 mm/HR (9-19)


Sodium 141 mmol/L (133-146)

Potassium 4.0 mmol/L (3.5 - 5.3)

Urea 4.2 mmol/L (2.5 - 7.8)

Creatinine 80 umol/L (45-84)

estimated GFR 66 ml/min/1.73m^2

AKI no previous creatinine

CRP 6.5 mg/L (0.0-5.0)


Short synacthen test 31.8.16

basal cortisol nmol/L 427

30 mins 763

6o mins 898

Sodium 140 mmol/L (133-146)

Potassium 4.2 mmol/L (3.5-5.3)

Urea 4.8 mmol/L (2.5-7.8)

Creatinine 70 umol/L (45-84)

estimated GFR (eGFR) 77 ml/min/1.73m^2

AKI (acute Kidney injury) No Warning

Older results :

Aug 2011

TSH 4.65

June 2015 prior to any medication being started.

At baseline, TSH 4.29

FT4 14.9, Thyroid Antibodies Peroxidase ABS + 112.7

Sept 2015 TSH 3.0

Nov 2015 TSH 2.11

4 Replies

mcooper In my opinion (and I am not medically trained but do self source T3 and add to my prescribed Levo), there is plenty of room for an increase in your T3. As long as FT3 stays in range there is no problem. Your endo is being over cautious, 5mcg T3 is a tiny dose equivalent to 15-20mcg Levo.

As you have autoimmune thyroid disease aka Hashimoto's, as confirmed by your positive TPO antibodies, are you addressing this by being strictly gluten free and supplementing with selenium L-selenomethionine 200mcg daily to try and help reduce the antibody attacks?

1 like

Hello SeasideSusie, thank you for taking the time to reply. I am not gluten free but am a lot more careful about what I heat. I am not supplementing with selenium so I will start to do that - I will put Selenium tabs on my Xmas wish list ! Thanks again :)


I'm not Hashi's so can't speak from experience of being strictly gluten free, but many members say it has helped enormously to reduce the antibodies. Some reading about it:

And about Hashi's in general in case you haven't seen them:

Some selenium supplements can have a rather unpleasant smell, the one I use doesn't smell and is frequently on 3 for 2

1 like

Thank you so much for the info above I will try the Selenium brand you mention above. And in the New Year will defo try to go gluten free :)


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