# Optimal time of day to test blood?



## Gwen1

Hi all, is there a best time of day to have blood drawn for thyroid hormone levels that would reflect the most accuracy? I take Levoxyl 125mcg at 
6:00 a.m. Endo tests TSH and Free T4. I know, I know, I'm working on getting the Free T3. -Thanks.


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## lainey

It really doesn't make much difference what time you do the blood draw. Yes, your TSH does vary slightly over the course of the day, but these changes are normal and overall not really significant.

People who take T3 medications sometimes will fast those before their test, because they are short acting.

In general, thyroid hormones in the blood reflect stored levels, thus the daily medication should not overly influence the blood test results.


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## Gwen1

Thanks lainey, I just want to cover all bases. I had been on a lowered dose for 4 years and felt horrible hypo, even tho endo said I was within range. Up until now, I haven't asked for copies of test results as I was entrusting his knowledge for my dosage requirements. I am currently feeling hyper, but don't know because last Oct. he raised dosage from 112 mcg. 6 days to 125 mcg. 7 days and said "see you in a year". -Gwen


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## Andros

Gwen1 said:


> Thanks lainey, I just want to cover all bases. I had been on a lowered dose for 4 years and felt horrible hypo, even tho endo said I was within range. Up until now, I haven't asked for copies of test results as I was entrusting his knowledge for my dosage requirements. I am currently feeling hyper, but don't know because last Oct. he raised dosage from 112 mcg. 6 days to 125 mcg. 7 days and said "see you in a year". -Gwen


I hope you get copies this time so you can post the results with the ranges.

Free T3 and Free T4 are the only accurate measurement of the actual active thyroid hormone levels in the body. This is the hormone that is actually free and exerting effect on the cells. These are the thyroid hormones that count.
http://www.drlam.com/articles/hypothyroidism.asp?page=3

And try your best to get the FREE T3.


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## Gwen1

Thank you, Andros. There is no question that I will ask for a copy of test results. The health system this endo is in also has a website we can go to that posts the results. But I plan on getting a copy before I leave my appt. If there is any dose adjustment, I am going to request that I be retested 8 wks., 3 months, and 6 months. The longer something goes on with me, my body tries to adjust and then I can't tell if it's me or if the medication needs adjusting. Will post ranges. I'm real curious about the Free T3 level. -Gwen


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## Octavia

For consistency, I always get my blood drawn first thing in the morning, before I take my Synthroid and before breakfast. That way, it's as close as I can get to "all other things being equal..." across all of the instances of labwork, if that makes sense.


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## Gwen1

Yes, before the lab technicians get tired or frazzled and lose our bloodwork!


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## Octavia

That, too!

What part of Northern Illinois are you in? I used to live in Rochelle, worked in DeKalb, studied at NIU.


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## Gwen1

No T3 Free test for me! Called doc office and asked if it would be O.K. to add that test to my labs and the nurse said the doctor doesn't usually test for t3 free on synthroid patients.  -Gwen


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## bigfoot

Yep, join the club. 

Most docs aren't very interested in the Free T3 test. They seem to push the TSH, sometimes the FT4, and very rarely the FT3. I think there is a lack of consensus on thyroid testing methods in the medical community. If you look at the new, lowered TSH ranges, even those have apparently been debated over the last few years.

Someday, sometime, somewhere... this will be realized as a legitimate medical problem and treated as such!


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