Wellness E-zine: What is Reverse T3 Dominance?

Reverse T3 dominance is a unique thyroid hormone imbalance. Thyroid function becomes sluggish, even though circulating levels of T3 and T4 are within normal test parameters. In this condition T4 is no longer converting to T3, but is being shunted towards the production of inactive 'reverse T3'. Reverse T3 then binds to the T3 receptor sites, inactivating metabolism and causing the typical signs & symptoms of hypothyroidism (low thyroid function).

Prolonged stress is the major cause of reverse T3 dominance. Unrelenting stress stimulates cortisol, which causes unhealthy transformation of T4 to reverse T3. Reverse T3 dominance persists even when your stress levels settle down and cortisol returns to normal. This is because the reverse T3 continues to inhibit the conversion of T4 to T3, further perpetuating production of the inactive form.

Testing for T3 measures both active T3 and reverse T3. T3 levels may appear normal, however a significant proportion may include inactive reverse T3. To overcome this false diagnosis specifically measuring reverse T3 will rule out reverse T3 dominance.

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Wishing you the very best of health.

Louise O'Connor - Naturopath