Total T3

Specialist

also triiodothyronine

What it isThe combined measurement of T3 that is bound to transport proteins plus the small free fraction.

DoesReports the full T3 pool, but is less clinically informative than Free T3.

GoodA mid-range total T3 with normal Free T3 suggests adequate tissue thyroid hormone availability.

BadSame transport protein distortions as Total T4 apply.

Standard

80–200 ng/dL.

Optimal

130–180 ng/dL (narrow target)

Modifiers

Same as Total T4.

How to optimize

within Thyroid