Free T3
The active thyroid hormone that actually sets your metabolic rate. This is the one that correlates with how you feel.
What the numbers mean
These are the ranges BioForge works to. They are not the same as a lab's reference range, which is built from the general population rather than from people who feel well.
What moves Free T3
Conversion from T4 depends on selenium, zinc, iron, calories and cortisol. Aggressive dieting, overtraining, illness and chronic stress all suppress T3 conversion — very common if you are dieting for fat loss.
Related markers in Thyroid
This page is educational and is not medical advice. Ranges are general and do not account for your history, medications or symptoms — a single number never decides a protocol. Your results are interpreted by a licensed clinician alongside everything else about you. Back to the Learning Center
Want to know where your numbers actually sit?
Every BioForge protocol starts from your own bloodwork. The first 15-to-30-minute call is free.