ask: Thyroide hormone test should be taken after my period?Do I have to fast ?

Hi Anon

Thanks for your question.

Are you having a scan? Assuming you are, you will need to fast several hours before the test, so if it's first thing in the morning, do not eat breakfast. Some doctors will tell you to fast three to four hours before the test, others say eight hours. Ask your doctor which is better for your case.

Make sure there is no way you could be pregnant (due to taking a dose of radioactive iodine for the test).

Also make sure you let your doctor know any medications you are on and take them as you normally would unless they would interfere with the results of the test. Discuss this with your doctor.

I'm unclear as to why you would need to take this test based on when you get your period. Were you advised to schedule the test this way?

Good luck with the test. Do you have suspected hypo or hyper active thyroid?

If you’re talking about a TSH test, then it doesn’t matter when that test is taken. It also doesn’t matter whether you eat beforehand or not.

Are you sure you’re talking about a TSH test and not an FSH test? The FSH test is done within days after your period finishes.

The TSH test measures how your thyroid is functioning; the FSH measures how your ovaries are functioning. Both measure hormones that are triggered by the brain, so they're alike in that way.