Thyroid UK
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Blood test results - to take or not to take meds before blood tests? - week 12 of treatment, still feel awful -

Hi, I am new here so please bare with me while I get used to how everything works. I'm new to the condition too, so not clued up with what's what.

I have suffered for years, at least since the birth of my child in 2010, with terrible fatigue, severe anxiety & panic, hair loss, joint pain, freezing cold, recurrent infections etc etc, the list is endless.. And was always told I was 'developing' an under active thyroid and my problems were put down to already suffering mental health problems.

Anyway, after feeling close to death over the past year or more, my doctor started me on levothyroxine 25, which was upped to 50 6 weeks ago, and I'm due my next set of bloods next week.

My last lot were:

Took my levothyroxine as normal on day of test

Tsh 5.20 (range 0.35-5.00 U)

Free t4 14.5 (range 9.0-21.0 U)

Tpo Ab 136.8 (range <<6.0 U)

Should I be abstaining from taking my levothyroxine on the day of blood test, and take it afterwards instead. Does the meds mask real Tsh levels? Will not taking this give a clearer picture?

I have been on this medication for around 12 weeks and apart from a tiny tiny barely noticeable little bit of energy, I do not feel any better and still suffering all of my symptoms and barely functioning.

My b12 was low last year, I had 5 pills a day for a few months then just been told it's low again and now on more pills and I think being tested for pernicious anaemia this time round.

Thanks in advance for any input and advice

8 Replies

You take the meds after the blood test because if you take it before your FT4 will be higher than without. Your TSH is still to high so the increase is good. You have antibodies which means you have Hashimotos disease. Please look it up, also the book of Izabella Wentz was really helpfull to me.

What was your B12 result? You can take sublingual tablets, take at least 1000mcg.

Did they test vitamin D and ferritin? This is often low with thyroid patients and you need them high. Not just to feel well but also for your body to convert T4 (inactive hormone) to T3 (active hormone).

You want the TSH around 1, FT4 in the upper range and FT3 as well. As long as FT3 isn't right (and the vitamins and minerals) you will feel unwell.

Good luck!


Hi Flower, thank you very much for your recommendations, I will check out the book for sure, and will skip taking the levothyroxine until after my next set of bloods next week.

My b12 is 180. I'm on only 2 cyano 50mcg per day this time around. Last time It was lower and had 5x1000mcg per day. My mum has pernicious anaemia which I think has flagged up for Dr to test me due to my positive TpoAb test. My MCH is just above range too, so I'm not sure if i can be 'developing' pernicious anaemia? Will see how the bloods come back next week.

I have not had the vitamin D or ferritin checked, if this is not included in this new set of bloods, I will request for it to be added in with the next. T3 has not been done either so I hope that's included too.

Thank you so much for your reply, I am now off to find that book as feel I must arm myself with info to hopefully understand better what's going on.



I don't know enough about PA to help you with that, sorry. But yes, if you've got one autoimmune disease than you can have more and PA is one of them. You are on a low dose of B12, you can take much more if you would like. I take 2x 1000mcg sublingual tablets a day.

We need to read and learn about the thyroid as doctors often don't know enough. Become your own specialist, always ask for a copy of your blood results.


If you're being tested for P.A. don't supplement with B12 yet.


Hi, I am sorry you are hypothyroid. I think you are feeling so unwell because your initial dose was low at 25mcg. 50mcg is usually a starting dose with 25mcg increases around every 4 to 6 weeks until you feel much better.

Don't take levo before your blood test, leaving about 24 hours between a dose and the blood test. Have the blood test as early as possible. If you've not had a Vit B12, Vit D, iron, ferritin and folate tested, ask for these as we are usually deficient.


Thank you Flower and Shaws

My gp decided to ease me onto the levo, starting very low, due to how severe my anxiety and panic is. I also have a fear of taking pills, both of which i need to get over now this is going to be a life long condition.

I am definetly not going to take the levo this time around before my blood test.

I had difficulty getting a copy of the last lot of bloods printed for my own records, hopefully my gp will agree to give me them all the time from now on.

I will not up my b12 dose for now, incase my gp has put me specifically on the low dose due to testing me for PA. Will see how that goes.

Thanks again to you both



Your doctor has put you on the wrong B12, anyway. It should be methylcobalamin, not cyno. Methyl is better absorbed. If he's going to test for PA, I would come off them, if I were you, until after the test.


Thank you greygoose. My Dr i dont think ran the test for PA in the end, my b12 is increasing ever so slightly by 7ng/l every few months. My b12 level is now sitting at 305ng/l ref(200-900) the highest its been in years


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