Blood draw

Hello, im travelling from Gloucestershire to London on tues for a blood draw at 12 noon. I won't take my levo the night before as usual and wait until after the draw but can i have a cup of tea and a few brazil nuts at around 8 am or will that skew the results? Im not worried about the food impacting the absorbtion of the levo for that day just if it will impact the blood results in any way.

My t3 was low in range last time and t4 was good. I have taken mercury pharma ( eltroxin and unbranded) for 9 years or so but for last 3 months ive been taking Activis. I feel a bit undermedicated even though im now taking 150 mcg. Ive put on a stone in weight but im also using bio identical hormones for hot flushes so could be that. I use a transdermal cream with estrogen, prog and test morning and evening and now take my levo in the middle of the night so there is a four hour gap between. 

I will get my ferritin, vit d and b12 tested too although they were all high in range last time. I guess im wondering if the bio identicals are impacting my t4/t3. Ive always been at the lower end of the range for t3 and t4 has always been high in range. Will post results when i have them.

4 Replies

  • I usually have my normal breakfast about an hour or so before the blood draw, it has no effect.  If eating affected your thyroid hormone levels every human and animal in the world would be hypothyroid for a few hours after eating!

  • Janiebell,

    TSH is highest early in the morning and drops after eating and drinking which is why early morning fasting tests are often recommended.  If you're not fussed about the TSH level there's no need to fast.

  • Thank you, Clutter. I was hoping you would respond! I know you are extremely knowledagable. Some time ago i managed to overdose myself for about 10 days at least on 300mcg of levo daily. You kindly replied and suggested i let the extra wash out of my system over 4 days which i did with no ill effects. What really shocked me was that i felt no different on double the meds. Is that normal?  I assumed i would go hyper. Am i right in thinking we go hyper if our t3 is above range? Im wondering if i dont convert well as my t3 is always low in range and my t4 is high in range. When i get these next results do you mind if i post them to you for your opinion? I know you are not a doctor, etc but you always have good advice. Many thanks, jane

  • Janiebell,

    You probably would have started feeling hyper if you hadn't reduced 300mcg fairly quickly.

    FT3 over range is biochemically hyper but often one doesn't *feel* hyper when over range.

    Low TSH, high FT4 and low FT3 indicate poor conversion.

    I won't comment on results via private messages but I'm happy for you to PM a link to a post you want me to comment on.

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