Reverse T3 Dominance
By Louise O’Connor, Naturopath
What is Reverse T3 Dominance?
Reverse T3 dominance is a thyroid hormone imbalance. It is a condition where hypothyroid symptoms exist, but circulating levels of T3 and T4 appear to be within normal test limits.
What is actually happening is T4 is no longer converting to T3, but is being shunted towards the production of inactive 'reverse T3'.
Reverse T3 slows metabolism and causes the typical signs & symptoms of hypothyroidism (low thyroid gland function).
What Causes Reverse T3 Dominance?
Prolonged stress is the major cause of reverse T3 dominance.
Unrelenting stress results in high levels of cortisol, the main hormone released by the adrenal glands in response to stress. Elevated cortisol inhibits conversion of T4 into T3, reducing active T3 levels. T4 is instead converted to reverse T3.
Reverse T3 dominance may persist even when your stress levels settle down and cortisol levels return to normal. This is because the reverse T3 continues to inhibit the conversion of T4 to T3, perpetuating production of the inactive T3 hormone.
Reverse T3 Blocks Active T3
Reverse T3 has the same molecular structure as T3 however it is a mirror image of T3 and therefore fits into the receptor upside down. This prevents the active T3 from binding to the receptor site and activating the appropriate thyroid response.
Reverse T3 Testing
A test for reverse T3 will identify high levels of the inactive form of T3. Under normal conditions T4 will convert to both T3 and reverse T3 and the body quickly eliminates reverse T3.
A specific measurement of reverse T3 is valuable in identifying excessive levels of reverse T3, which will lead to Reverse T3 Dominance.
Treatment of Reverse T3 Dominance
If reverse T3 dominance is diagnosed it is usually treated by prescribing active T3. This reduces the symptoms of low thyroid function and will also slow TSH production, which in effect reduces the bodies own production of T4.
With little or no T4 left in the system reverse T3 production eventually decreases. Further, the conversion of T4 into T3 will then no longer be inhibited by the reverse T3 allowing the appropriate activation of T4 into the active T3 form.
It is important that T4 (thyroxine) and Armour Thyroid medication or other natural thyroid extracts are not used for this condition. Supplemental T4 may also convert to reverse T3, further driving this thyroid hormone imbalance.
Natural Thyroid Treatment
It is possible to use a holistic approach to treat your thyroid, with treatment more effective when all aspects of your health are addressed. High levels of stress, toxicity, adrenal exhaustion, hypoglycemia and/or low sex hormone levels are the key factors that lead to reverse T3 dominance.
Your first step towards recovering thyroid health is to choose a natural thyroid diet. It is vital to avoid the foods that damage your thyroid. Read about this in the ebook called The Natural Thyroid Diet.