Thyroid
Free T3/Reverse T3 Ratio
Unit: ratioID: T005
What This Test Measures
Balance of active to inactive thyroid hormone
Conventional vs. Functional Optimal Range
Conventional "Normal"
>20 ratioYour doctor says you're "fine" anywhere in this range
Functional Optimal
>20 ratioThis is where you actually feel great
The gap between these ranges is why you feel terrible with "normal" labs. Conventional medicine waits for disease. Functional medicine optimizes for health.
Gabriel's Take
This ratio is CRITICAL. Calculate: (Free T3 × 100) / Reverse T3. Need >20 for good cellular thyroid function. Below 20 = tissue-level hypothyroidism even with normal TSH. This is the metric conventional docs miss that explains why you feel terrible with "normal" labs.
When This Test Is High
Better thyroid function, good T4-to-T3 conversion
When This Test Is Low
Poor conversion, metabolic resistance, cellular hypothyroidism
Related Conditions
Chronic fatigue, weight issues despite normal thyroid labs
Recommended Follow-Up
Address root causes: stress, inflammation, gut, liver support