Your Free T3 to Reverse T3 Ratio and Stress

Looking at the free T3 to reverse T3 ratio (FT3:rT3) helps assess what is happening with your thyroid "at the moment." A lower ratio suggests an increase in the production of reverse T3, which can occur under times of stress, critical illness, starvation, or liver dysfunction. Reverse T3 is an inactive form of thyroid hormone, and can "put the brakes" on metabolism. A certain amount of reverse T3 in circulation is normal.

However, as rT3 production increases, the amount of free T3, the metabolically active form of thyroid hormone, declines. It is often due to temporary changes in the hypothalamus-pituitary-thyroid axis as the body mobilizes resources to fight the stressor at hand.

Want to Learn More?

CLICK HERE to learn more about the Free T3 : Reverse T3 Ratio, health consequences, optimal ranges, etc.