What do your Total T4 levels mean?
The short answer
Nobody we follow has said what your Total T4 should be. It comes up on the shows, but never with a number.
Your lab prints 4.5–12 µg/dL. That range exists to catch disease, not to describe your best.
What Total T4 measures
All the main thyroid hormone in your blood, both bound and unbound.
Binding proteins shift with pregnancy and medication, so the free form is often the clearer read.
Checked against MedlinePlus — Thyroxine (T4) Test.
Common questions
What is a normal Total T4 level?
Most US labs print 4.5–12 µg/dL. Your report grades you against that range. It exists to catch disease, not to describe your best.
What does your Total T4 number mean?
Under 4.5 µg/dL, your report marks it low. Between 4.5 and 12 it prints as normal. Over 12, your report marks it high. Nobody we follow has drawn a line inside that range.
What does the Total T4 test measure?
All the main thyroid hormone in your blood, both bound and unbound. Binding proteins shift with pregnancy and medication, so the free form is often the clearer read.
Why is there no target here?
Because nobody we follow has named a number for Total T4. If that changes, it will be here.