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Thyroid

Free T3

Also written as Free triiodothyronine.

Extended panel — run periodically

What it indicates

The unbound form of the more active thyroid hormone.

Why a series helps

It responds to illness and to energy intake, so repeated readings separate a temporary dip from a pattern.

What this page does not tell you

What a particular Free T3 result means depends on you: your history, your medication, why the test was taken. Ziro does not interpret results for individuals and does not diagnose. If something in your results warrants a conversation, that conversation is with a doctor, and your results are downloadable so you can bring them.

Others in thyroid

The hormones that set the pace of your metabolism.