First time posting on here. I have seen many people recommend having thyroid blood tests early morning before taking Levothyroxine. Does this make a big difference to the results?
I am due a thyroid blood test, my problem is I am housebound so my GP arranges for a district nurse to come out to my house to do all my blood tests.
The problem is they don’t let me know when they are coming and can turn up any time within approx 2 weeks. This means I have always taken my Levothyroxine for the day before I have the blood test that day.
Does this make a major difference to my results?
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AlphaWolf5195
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Most NHS doctors dose by TSH, and often that is the only thing they test. You might be lucky and get your FT4 tested, but rarely FT3 as well, unless your TSH level is abnormal. If you want to avoid a dose decrease then TSH is at its highest daytime levels around 9am.
After that it decreases. Food and drink can also lower TSH, which is why we recommend fasting, drinking only water and not taking Levo until after your test. Obviously as you are at the mercy of the district nurses then you probably wont be able to follow forum protocols.
The NHS doesnt prioritise thyroid blood tests in the same way it does other blood tests, ie like fasting glucose tests. They dont think time of day matters. However thyroid patients know it does 🤫
Time of day affects TSH but it starts to settle down after 10am. There is no reliable evidence that fasting has much effect on TSH so I wouldn't fast during the day as you don't know what time they will come. Taking you levothyroxine a few hours before taking the blood will have a small effect, you could simply switch to taking your levothyroxine at bedtime.
Medichecks and BH also offer private blood draw at clinic near you, or private nurse to your own home…..for an extra fee. You would need to ensure they could be there at 9am LATEST to do test
Although I have asked the district nurses in the past if they can let me know when they will be coming they never do.
I have never been given my actual thyroid test results in the past, although I will make sure to ask for them this time. I’ve just been told that my Levothyroxine either needed increasing or decreasing or my result was normal.
I have been on Levothyroxine for over 15 years.
At the moment I take 125mcg (100 mcg Accord plus 25mcg Wockhardt) Levothyroxine one day and then just 100mcg Levothyroxine the next and alternate the dose each day. I have been on this since approx January 2023, prior to that I was on 125mcg every day.
I take 100mcg B12 (prescribed), Vitamin D (prescribed), Vitamin C + Zinc, Calcium, Omega 3 and have just started taking Magnesium.
My GP is arranging a full range of blood tests including thyroid which should be done within next 2 weeks.
I also have several other health conditions for which I am prescribed other medications.
Unfortunately I can’t afford to pay for private tests so have to rely on the NHS.
You presumably are aware Levothyroxine is an extremely fussy hormone and should always be taken on an empty stomach and then nothing apart from water for at least an hour after
Many people take Levothyroxine soon after waking, but it may be more convenient and perhaps more effective taken at bedtime
No other medication or supplements at same as Levothyroxine, leave at least 2 hour gap.
Some like iron, calcium, magnesium, HRT, omeprazole or vitamin D should be four hours away
(Time gap doesn't apply to Vitamin D mouth spray)
If you normally take levothyroxine at bedtime/in night ...adjust timings as follows prior to blood test
If testing Monday morning, delay Saturday evening dose levothyroxine until Sunday morning. Delay Sunday evening dose levothyroxine until after blood test on Monday morning. Take Monday evening dose levothyroxine as per normal
I do know how to take Levothyroxine and the amount of time between taking it and other medications but thanks for checking that I did as it’s very important.
My daughter is a manager at a Pharmacy, so she makes sure I know exactly how and when to take all of my medications (several I take do interact with others I take so I have to be very careful).
The articles you listed about taking it at night were very interesting, it would make my life so much easier to take it at night as I have other medications I take as well that have to be 4 hours apart and/or must be taken on an empty stomach and an hour before food etc.
I will talk to my daughter about taking it at night and see what she says, also whether it would affect any of my other medications to take it that way.
You might not be able to control when your bloods are done, but this graph shows how tsh levels drop and then rise again after taking levo. If your bloods are taken at a tsh low, your GP might get skittish and tell you your dose needs reducing. If that happens, but you don't feel its necessary, show them this graph and explain you'd just taken your levo. Knowledge is power!
Thanks for the graph it is very interesting, this could be why sometimes in the past I have my dose altered because the time between taking my levothyroxine and the blood test is never the same.
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