Thyroid meds before labs?

[LeanGuy]

Typically do you guys take your thyroid meds the morning before labs, or wait until after? I imagine T3 would spike if taken before. T4 probably not so much.

[Dadnatron]

Get early draw... don't take your meds. Take meds only on an empty stomach to maximize consistency of absorption.

Every draw you get should BEST be early in the am ie 7-9am. This will allow for the most consistency between draws with the least 'variables' between activities food intake during the different days.

I do every draw between 7-8am. You beat the crowds... and can eat sooner!

:thumbup:

[pmgamer18]

This is what my Dr. has told me to do for yrs. And if your on Iron pills stop them about 5 days before labs.

Get early draw... don't take your meds. Take meds only on an empty stomach to maximize consistency of absorption.

Every draw you get should BEST be early in the am ie 7-9am. This will allow for the most consistency between draws with the least 'variables' between activities food intake during the different days.

I do every draw between 7-8am. You beat the crowds... and can eat sooner!

:thumbup:

[JanSz]

This is what my Dr. has told me to do for yrs. And if your on Iron pills stop them about 5 days before labs.

After I stopped taking iron pills
and started on UNI-LIVER
my Ferritin finally started going up.

..

[LeanGuy]

This is what my Dr. has told me to do for yrs. And if your on Iron pills stop them about 5 days before labs.

Really... so iron days before testing may show false increase in ferritin?

[LowT]

All that matters is what your doc expects to see. Test when they want you to so they can interpret the results.

[wondering]

This is the answer.

You're correct. Taking the med (assuming there is T3 involved) will bump T3 due to 7 hour half-life, but no difference in T4 due to 7 day half-life.

Dr. J likes to test 2 hours after taking so he can "see where you live".

If you want to test how much T3 you are converting from T4, then don't take your pills.

If you are strictly on T4 meds, then I dont think it makes a difference what you do.


All that matters is what your doc expects to see. Test when they want you to so they can interpret the results.

[Dr. John Crisler]

This is the answer.

You're correct. Taking the med (assuming there is T3 involved) will bump T3 due to 7 hour half-life, but no difference in T4 due to 7 day half-life.

Dr. J likes to test 2 hours after taking so he can "see where you live".

If you want to test how much T3 you are converting from T4, then don't take your pills.

If you are strictly on T4 meds, then I dont think it makes a difference what you do.If you take your thyroid meds, you are measuring the T3 that is in your meds (in suppressed patients), plus that which is being converted by enzyme D1 from the bult-up T4, and the daily dose T4. Remember the short (7 hour) half life of the T3 from the daily dose of thyroid med.

If you do not take your meds, you are measuring the built up level of T4 (7 day half-life), and the T3 converted from the built-up T4 (not the T4 from the daily dose). Therefore you are measuring the activity of D1.

I draw either, or both, depending upon the case.

[LeanGuy]

If you take your thyroid meds, you are measuring the T3 that is in your meds (in suppressed patients), plus that which is being converted by enzyme D1 from the bult-up T4, and the daily dose T4. Remember the short (7 hour) half life of the T3 from the daily dose of thyroid med.

If you do not take your meds, you are measuring the built up level of T4 (7 day half-life), and the T3 converted from the built-up T4 (not the T4 from the daily dose). Therefore you are measuring the activity of D1.

I draw either, or both, depending upon the case.

Excellent response.

[pmgamer18]

How high do you feel you need your Ferritin mine is at 75 and I feel fine.
But I did go back on this.
Cypress Ferrous Fumarate 324 mg, 2 Tablets per day.

After I stopped taking iron pills
and started on UNI-LIVER
my Ferritin finally started going up.

..

[pmgamer18]

Right do go over this with your Dr. in my case if I take the Iron the days before the labs my Iron and CBC levels all come in in error.

All that matters is what your doc expects to see. Test when they want you to so they can interpret the results.