fT3 in Serum

Free T3 is the active thyroid hormone driving metabolism (the "gas pedal").
Also known as:
Free Triiodothyronine
S-fT3
Free T3
.

fT3 ranges

Interpret your result
"Normal" lab range for fT3 is between 2 and 4.4 pg/mL:
2
4.4
According to Peter Attia, fT3 should be between 2.8 and 4 pg/mL:
2.8
4
According to OptimalDX, fT3 should be between 3 and 3.5 pg/mL:
3
3.5
According to Rupa Health, fT3 should be between 3 and 4 pg/mL:
3
4
Optimal thyroid health was associated with fT3 between 2.62 and 4.42 pg/mL:
2.62
4.42
Optimal range
Optimal range for fT3 appears to be between 2.8 and 4 pg/mL:
0
2
2.8
4
4.4
8

Images:

FT3 decrease during aging

FT3 decrease during aging

Chinese population with sufficient iodine intake

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Zsolt Szabo
Zsolt Szabo
Precision Health Consultant for Longevity Clinics, Biohacker, and Software Engineer

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I am particularly interested in research on biomarkers associated with all-cause mortality and on defining optimal reference ranges.