Levothyroxine reduced!: Hello everyone, I went to... - Thyroid UK

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Levothyroxine reduced!


Hello everyone, I went to the nurse for an asthma review and whilst I was in there I mentioned to her that I was due a blood test for my thyroid but I didn't have a blood test form. She said she could do it there and then as she didn't have anyone in after me. I had not long took my tablets for that day which I normally miss when I know I have a blood test.

My doctor rang me a couple of days after to say I was overmedicated and that I should go down 25mg.

I mentioned to my doctor that I had took my tablets that morning and she said it doesn't matter, it won't make a difference. I've been feeling ok on 150mg and I'm worried that if I go down I'm going to start getting a lot of the symptoms I had before the worst being extremely tired.

Will 25mg less make a big difference? And should I have not had my levothyroxine before my blood test or is my doctor right, that it doesn't make a difference?

14 Replies

Suggest you get printed copies of the actual blood test results.

See what's actually been tested

For full evaluation you need TSH, FT4, TT4, FT3 plus TPO and TG thyroid antibodies. Plus vitamin D, folate, ferritin and B12.

Just dosing according to a TSH or TSH and FT4 is inadequate

If FT3 and FT4 are in range dose does not need reducing

What time of day was this test done?

Thanks for replying.

I'll have to ask for my results.

The blood test was about 10am! I took my levothyroxine that morning about 7ish.

I just don't think I'm over medicated. Well I don't feel like I am anyway.



Do you have your actual results from the test (with reference ranges)?

Taking your Levo before the test wouldn't have made any difference to your TSH but would have given a false high FT4.

What time was the test and did you eat before hand? That's what affects TSH.

Thanks for replying,

I did have breakfast an hour after taking my levothyroxine. I don't have any results. I hardly see my doctor she calls me when something needs adjusting.

in reply to Jenna_marie


Eating will have lowered your TSH to some extent and with a false high FT4 that might be the cause of your GP wanting to reduce your dose.

Pop along to your surgery and ask at reception for a print out of your results then post them on the forum. Ask for previous results too so you can compare them.

Ok, I will do!

Thank you!

They always say taking tablets makes no difference to results. But it does!

Almost as if they don't know anything about it ;)

Hi, my dr also said it didn’t matter if I had taken my Levothyroxine before a multiple,blood test ..but previously I,had always, taken it after and will do so next time even it if have a test for different things at the same time ...so I learn a lot,on here


Even if it you needed to reduce, why by 25 micrograms?

The only reason to reduce by 25 micrograms is the dosages that tablets come in. Which is a rubbish basis. If you do have to reduce at all, why not by 12.5 micrograms? You would need 100 + 25 + a split 25. Or alternate 150 and 125.

When you have been on a stable dose, it is so very silly make big changes. (Not you being silly, but a doctor doing that.) Unless seriously over-dosed, make the smallest possible/practical change, wait about six weeks, test again and review.

By the way, it is microgram (mcg) - not mg (milligram)!


I agree!

Yes and I did mean mcg! Thanks!

Refuse to reduce, say you feel well on 125 and you are not willing to compromise your health by taking less medication when you feel fine. Your blood test was not comparable with earlier ones used for your dosage your doctor is being unscientific. Demand another blood test and do it as you would normally early am fasting & no levo. Don’t let them bully you like this

in reply to TSH110

I'll try but I know she won't change it! My doctor is pretty abrupt with me anyway. Never mind when I'm trying to tell her I think she's doing something wrong.

in reply to Jenna_marie

It is your right to refuse any reduction. If you were ever under an endocrinologist that set the higher dose you can demand to see them about it. A GP tried to halve my dose after suffering for 9 months trying to get optimised under the care of an endocrinologist. I called the endos secretary she advised to demand a referral back to them - the GP dropped the reduction like a hot brick when I told her I had been advised to get referred back to them. They are just playing about with our health and an expert/ specialists hard graft to get us back to health, appearing to know nothing and they need slapping down. I would see someone else if you can she sounds like a total nightmare with a highly dubious approach and we are paying her £100k a year 🙄

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