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Total thyroxine in the blood
Medical expert of the article
Last reviewed: 05.07.2025
T 4 (thyroxine) is the main hormone of the thyroid gland. Its concentration in the blood exceeds that of T 3 by 60 times. The half-life is 5-7 days.
Reference values (norm) of total T 4 (thyroxine) concentration in blood serum
Age |
T 4, nmol/l |
Newborns: |
95-168 |
0-5 days |
152-292 |
11-15 days |
126-214 |
>15 days |
93-186 |
Children: |
|
1-5 years |
94-194 |
5-10 years |
83-172 |
Adults 10-60 years |
|
Men |
59-155 |
Women |
71-142 |
>60 years |
65-138 |