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Thyroid UK
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Can I please have your opinions on PTU dosage for Graves Disease (second set of blood test results)?

Hi All,

Thank you very much for your help on my first post which related to me being newly diagnosed with Graves disease on March 5th 2015 and worrying about continuing breastfeeding (all good there, baby got tested and his thyroid is fine).

Here is my first set of results (Mar 5th)

TSH<0.01 (0.35 - 4.94)

Free T4 40.60 (9.01-19.05)

Free T3 34.80 (2.63 - 5.7)

And here is my new set of results - (Apr 13th)


Free T4 12.3 (12-22)

Free T3 5.7 (I don't have the range but the Endo said it's in the middle of the range)

I also managed to get vit D tested and the GP says it is low at 70.8 nmol/L while the Endo says anything above 50 is normal - can anyone shed any light on this? Since 29th Mar I have been taking 4,000 iu D3 per day.

So, dramatic change on the thyroid levels and the Endo looked a bit shocked, he even started to doubt the original diagnosis but I did have the test for antibodies so it is definitely Graves. But based on the results above I am euthyroid except for the TSH number.

I have been taking Carbimazole 15mg for 4 days from 22nd Mar to 25th Mar (NHS mistake as they did not realise that I was breastfeeding) and then changed to PTU 100mg twice a day plus 30mg Propranolol 3 times a day and my pulse is now around 75. I am feeling quite well except for being tired because the baby is up most of the night (still).

Now for the supplements I am taking - Omega 3 high concentration, B-complex, acetyl-l-carnitine, vit C, Selenium, vit D3 and Ca/Mg with D3.

The endo wants me to halve the PTU dose to 50mg twice a day but I worry about becoming hypo - what are your thoughts on this, please?

Thank you,


6 Replies

Just to add the endo wants me on new dosage for two weeks then to get blood tests done.


Danutza, you are more likely to become hypo if you don't cut the dose of PTU as the endo recommended. Your TSH remains suppressed but your FT4 is low in range although your FT3 is mid range. On your current dose they will drop and you will become hypothyroid. Halving the dose should see your FT4 improve and hopefully won't increase your FT3 too much. Testing in 2 weeks time will indicate whether the dose is appropriate or needs tweaking.

VitD is optimal 75-200 so continue supplementingfor another couple of months. Most of us are happy with vitD around 100.

Good to hear you are feeling well and your baby's thyroid is good.


Thank you, Clutter. I feel relieved the baby is fine, and I only worry about the numbers dropping so fast and wondering if even half the dose is too much. The Endo said I would know if I am going hypo, but wouldn't that be too late if I start getting the symptoms? I'll see how it goes, and I'll continue the Vit D. Oh, I did get a superficial vein blood clot in the last week but both the GP and the endo are pretty certain it has nothing to do with the current situation - I don't believe in coincidences though, but who knows? Oh, my solar urticaria seems to have improved a bit, I wonder if it is the vit D supplementation that 's helping.


I agree with clutter - too much anti thyroid drug for too long and you will become hypo - cutting it back should stop that so give it a try and see what happens and being tested again in two weeks time will let you see what is happening.

Glad the baby is fine after the carb. I hope the endo was suitably mortified. Do you feel any different on PTU?

Did your GP give you vit D to take if he felt yours was low?


Hi, thank you for replying. I am worried that I've become euthyroid very fast and half the dose is still too much, but I guess we shall see.

The endo was mortified or scared or both for putting me on Carb while breastfeeding and suddenly he was able to see me not on April 20th for the first appt, but pretty much the Monday following our conversation on Wednesday 25th April!

And neither the GP or the Endo followed up on the low vit D result! I'll probably hassle the GP on that, to suggest an appropriate dose while I am continuing to supplement on my own!

I can tell you this, it's been a proper roller coaster with the medical profession ever since my second pregnancy... lots of near misses.


Grr - first replied just disappeared while I was looking at it. So annoying.

Anyway, I was saying in future your endo needs to ask every woman of childbearing age whether or not they are pregnant or breast feeding. It's like way back when I was young I was always asked fir the date of my period before they would even consider giving me an x-ray. At least they rushed you forward and got you sorted out and the baby is fine. Roller coaster doesn't even begin to describe your experience. Funnily enough that is exactly what my endo said to me when I was complaining about my hair falling out and my finger nails disintegrating - I had been on a high dose of carb for too long without being tested before I got to see an endo - I went from being very hyper to being very hypo in a couple of months.

I thought euthyroid was good though but I'm not medically qualified. Someone who knows will come along and tell you.

I would imagine they will be rolling out a red carpet when you arrive from now on.

I honestly don't think the average doctor / endo cares about low vit D - one endo I saw refused my request to test it - although he did test my B12 - he said he thought all this fuss about vit D was just 'fashionable' and if I could bring him proof he would consider it. As it was a teaching hospital and I saw someone different every time I never saw him again. I just use City Assays to test my own and use a vit D spray every day - at the moment I think I'm using a 3000 one although I tend not to use it every day now, my D is nice and high.

Keep well and enjoy Your little ones although with Graves it must be very hard work. 😊

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