<qa>  What is the TSH concentration of participants who have been on a stable dose of thyroid supplement- Thyroid-stimulating hormone TSH concentrations outside the range of 0.30-8.0 UlUmL. NOTE: Participants who have been on a stable dose of thyroid supplementation for at least the past 3 months, have medically appropriate TSH values, and are clinically euthyroid may participate in the study. 