Best time for blood retest: Hi I've been on levo... - Thyroid UK

Thyroid UK

140,948 members166,084 posts

Best time for blood retest

Holly99 profile image
6 Replies

Hi I've been on levo for 6 weeks and due to have a blood check on Monday at 9am. When should I take my levo and should I fast?

Written by
Holly99 profile image
Holly99
To view profiles and participate in discussions please or .
Read more about...
6 Replies
silverfox7 profile image
silverfox7

Because doctors are so fixed on looking at your TSH reading and want to get it higher then the ideal situation is to give your blood when it's as high as possible in the hope they don't want to lower your medication in an attempt to do this. The level changes throughout the day so the best time to make your appointment is as early as possible. Whether you have eaten or not also changes the value do eating lowers the TSH so do not eat before your test.

So best time is as early as possible and starved.

SlowDragon profile image
SlowDragonAdministrator

Also don't take Levo in 24 hours before hand.

If you normally take it at bedtime, or on waking, delay taking it until immediately after blood test.

eeng profile image
eeng

9am is a good time. The earliest possible is even better. Don't take your Levothyroxine for 24 hours before the test, you can take it as soon as the test is done. It's best not to have breakfast - you can drink water. Of course you can have breakfast after the test.

Apparently your TSH is highest first thing in the morning and drops after a meal and after taking Levothyroxine, and what you want is a nice high TSH so that you don't end up undermedicated.

Gardenofeden profile image
Gardenofeden in reply toeeng

Is it ok to have blood taken 26 hours after last dose?

That's how i have been doing it for years😑

Thx

eeng profile image
eeng in reply toGardenofeden

of course. 24hours is a minimum.

Glynisrose profile image
Glynisrose

Don't take your levo within 12 hours of a blood test, it will skew the results.

Not what you're looking for?

You may also like...

Time to Retest - T3 Advice Needed

Hi I need to run another blood test later this week to check on things. I am not sure how to do...
FancyPants54 profile image

Method for first retest on T3/T4 combo?

Hello T3 users. I have been on a combo of T3/T4 for 6 weeks next week and need to retest. I...
FancyPants54 profile image

Best time for blood tests?

Hi I have seen a few posts recently that it's best to have bloods done at 9am. All my previous...
Macey2009 profile image

Iodine in Multivitamin and best time to take levo

Hi I have received some really excellent advice over the last few days but now have another couple...
lucylocks profile image

Best time for blood tests?

Last time i had my bloods tested for a possible thyroid issue, it was triggered by sudden weight...
Lambchop35 profile image

Moderation team

See all
PurpleNails profile image
PurpleNailsAdministrator
SlowDragon profile image
SlowDragonAdministrator
RedApple profile image
RedAppleAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.