Reverse T3

What this laboratory test evaluates

DetailsReverse T3 (rT3) is an inactive form of the thyroid hormone T3 that is produced under stress or illness when the body converts T4 into rT3 instead of active T3. It is used to assess thyroid hormone conversion efficiency and may help identify non-thyroidal illness or functional hypothyroidism.

What type of sample is required for this test?Serum

Test ResourcesFor more information, please consult your healthcare provider.

Additional test information

Reverse T3 (rT3) is an inactive form of the thyroid hormone T3 that is produced under stress or illness when the body converts T4 into rT3 instead of active T3. It is used to assess thyroid hormone conversion efficiency and may help identify non-thyroidal illness or functional hypothyroidism.

Collection and processing

• Sample type: Serum
• Fasting: No
• Estimated laboratory processing: Results should arrive 4 – 6 business days after the lab receives samples.

How Sunridge uses laboratory information

Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.

Before requesting this test

Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.