When do I retest?: Hi everyone, Can you help me... - Thyroid UK

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When do I retest?

mids_thyman profile image
5 Replies

Hi everyone,

Can you help me please?

I recently posted on here about my frustrating experiences with my doctor, which resulted in me increasing my Levothyroxine on my own.

It's been 8 weeks now since I made the change. When do I need to re-test my levels with a private blood test?

Thanks in advance,

Mids_Thyman.

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SovietSong profile image
SovietSong

Hi, think 6-8 weeks is the norm as I've been advised on here.

SovietSong profile image
SovietSong

Are you feeling the benefit of the increase thyman? What dose were you on and what did you up it too?

SeasideSusie profile image
SeasideSusieRemembering

mids_thyman

6-8 weeks tends to be the time gap suggested here. Some of us need a few weeks extra, I have found that I may need 10 weeks for levels to completely settle. I would say that now is the time for you to test.

Remember to follow our advice when testing thyroid:

* Book the first appointment of the morning, or with private tests at home no later than 9am. This is because TSH is highest early morning and lowers throughout the day.

In fact, 9am is the perfect time, see first graph here, it shows TSH is highest around midnight - 4am (when we can't get a blood draw), then lowers, next high is at 9am then lowers before it starts it's climb again about 9pm:

healthunlocked.com/thyroidu...

If we are looking for a diagnosis of hypothyroidism, or looking for an increase in dose or to avoid a reduction then we need TSH to be as high as possible.

* Nothing to eat or drink except water before the test - have your evening meal/supper as normal the night before but delay breakfast on the day of the test and drink water only until after the blood draw. Certain foods may lower TSH, caffeine containing drinks affect TSH.

* If taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw. If taking NDT or T3 then last dose should be 8-12 hours before blood draw, split dose and adjust timing the day before if necessary. This avoids measuring hormone levels at their peak after ingestion of hormone replacement. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 3-7 days before any blood test. This is because if Biotin is used in the testing procedure it can give false results (most labs use biotin).

These are patient to patient tips which we don't discuss with phlebotomists or doctors.

SlowDragon profile image
SlowDragonAdministrator

Looking at previous post……you haven’t had thyroid antibodies tested yet?

Get full thyroid including thyroid antibodies and vitamin testing done

Vitamin D, folate, ferritin and B12

What vitamin supplements are you taking

Do you always get same brand levothyroxine at each prescription

Test thyroid early morning and last dose levothyroxine 24 hours before test

mids_thyman profile image
mids_thyman

Hi everyone, Thanks.

I've ordered a test and it's arrived today. I think I need to send it off on Monday if I remember correctly with MonitrMyHealth. Unfortunatley the full-health check doesn't include TPO antibodies so I'll arrange that seperately. As it happens my doctor is sending me for a coeliac test next week.

I also remember last time being advised to stop taking supplements for a while before the tests. For example I'm currently taking a folate supplement. How long do I pause them for?

Thanks, Mids_Thyman

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