# TSH testing



## GD Women (Mar 5, 2007)

*NACB: *Laboratory Support for the Diagnosis and Monitoring of Thyroid Disease
The ideal time for TSH testing is not influenced by the time of day the L-T4 dose is ingested
santana0612.files.wordpress.com/2009/09/tsh.pdf

*American Association for Clinical Chemistry *
Levothyroxine (L-T4) replacement therapy TSH testing can be performed any time of the day and is not influence by L-T4 ingestion. 
The time of the day that the blood is drawn has minimal effect on TSH levels.
http://www.aacc.org/events/expert_access/2005/thyroid/Pages/qanda.aspx

*medscape*
The ideal time for TSH testing is not influenced by the time of day the L-T4 dose is ingested. 
http://www.medscape.com/viewarticle/452667_5

*medhelp*
It should not effect the TSHPituitary and tsh and would have small impact on T4 test -- so ok to take med morning of labs. 
www.medhelp.org/posts/Thyroid-Cancer.../

for TSH testing is not influenced by the time of day the L-T4 dose is ingested.
www.liebertonline.com/doi/pdf/10.1089/105072503321087015

Thus when monitoring L-T4 in central hypothyroidism it is important to wait at least 9 hours after dosing.

*The key thing is consistency: *take the same dosage at the same time, with the same interval from foods, each day. This ensures that your blood tests reflect the true situation within your body, and your doctor is then in a better position to prescribe the correct drugs and dosages.


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