0.5 mL serum (labeled PRE) and 0.5 serum (labeled POST) in red top or serum separator tubes.
Test Description
T4, T3, Post Pill T3 and Post Pill T4
The submission of two separate serum samples (baseline T3/T4 and a post T3/T4). The second sample (post T3/T4) is obtained following a specific protocol of oral liothyronine sodium administration.