Inverted T3, also known as reverse T3, is a thyroid hormone that is produced in the body as a result of the conversion of T4 (thyroxine).

Unlike T3 (triiodothyronine), which is the active thyroid hormone that is responsible for regulating metabolism, reverse T3 is a biologically inactive form of the hormone that can potentially interfere with normal thyroid function and metabolism.

What Causes Inverted T3 Levels to Increase?

There are a number of factors that can contribute to an increase in reverse T3 levels. These may include:.

Stress
Starvation or fasting
Low-calorie diets
Chronic illness or infection
Acute injury or trauma
Excessive exercise or physical exertion
Certain medications, such as beta blockers and corticosteroids
Genetic predisposition or underlying thyroid dysfunction

How Does Inverted T3 Impact Metabolism?

When reverse T3 levels become elevated, it can lead to a number of metabolic changes that may contribute to weight gain, low energy, and other symptoms of thyroid dysfunction. Some of the ways in which inverted T3 can impact metabolism include:.

Lowered metabolic rate: One of the primary effects of reverse T3 is to slow down the body’s metabolic rate. This means that fewer calories are burned at rest, making it easier to gain weight.
Reduced insulin sensitivity: Elevated reverse T3 levels have been shown to decrease insulin sensitivity, which can lead to elevated blood sugar levels and increased risk of metabolic syndrome and type 2 diabetes.
Impaired thyroid hormone utilization: Reverse T3 can also interfere with the body’s ability to utilize T3, which is the active thyroid hormone that is responsible for regulating metabolism. This can result in symptoms such as fatigue, weight gain, and difficulty losing weight.
Increased inflammation: Elevated reverse T3 levels have also been linked to increased inflammation in the body, which can contribute to a number of chronic health conditions.

How is Inverted T3 Measured?

To determine if you have elevated levels of inverted T3, your healthcare provider may order a blood test to measure your thyroid hormone levels. This test may include measurements of TSH (thyroid-stimulating hormone), T4, T3, and reverse T3.

If your reverse T3 levels are found to be elevated, your healthcare provider may recommend additional testing to determine the underlying cause of the dysfunction and develop an appropriate treatment plan.

Treatment Options for Elevated Inverted T3

The treatment options for elevated reverse T3 levels will depend on the underlying cause of the dysfunction.

In some cases, lifestyle changes such as reducing stress, improving sleep, and adopting a balanced diet may be sufficient to restore normal thyroid function.

In other cases, medication or supplements may be necessary to regulate thyroid hormone levels. These may include thyroid hormone replacement therapy, selenium supplementation, or the use of medications that help to reduce reverse T3 levels.

The Bottom Line

While inverted T3 is a natural byproduct of the body’s conversion of T4, elevated levels of the hormone can potentially impact metabolism and contribute to symptoms of thyroid dysfunction.

If you are experiencing unexplained weight gain, fatigue, or other symptoms of thyroid dysfunction, it is important to speak with your healthcare provider and get tested for inverted T3 levels.