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Midwest · Reverse T3 Test – rT3 Testing

Reverse T3 Test – rT3 Testing in Minnesota

This page explains the reverse t3 test – rt3 testing, what it measures, and how to order it. The Reverse T3 blood test measures a form of thyroid hormone that can help clarify unusual thyroid function test results. It is often used alongside other thyroid tests to give a fuller picture of how the body is handling thyroid hormone.

Sample typeBlood and/or urine at a collection lab
ReferralIncluded — no referral from your own doctor needed

Lab requirements in Minnesota

Here is what you need before ordering and completing the Reverse T3 Test – rT3 Testing in MN. Review each item and confirm the details with the collection lab.

Physician's order
Included. A physician's order is required for lab testing and is provided for you by our partner's physicians — no referral from your own doctor is needed.
Fasting
Some tests require fasting or avoiding certain foods or drinks beforehand. You will be informed when you order — confirm the details with the collection lab.
Preparation
Preparation instructions can vary depending on the laboratory and the other tests being performed at the same time. Always follow the specific instructions provided by the collection lab or…
Sample & visit
A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
Identification
Bring the lab requisition form from your account. The collection lab may also ask for a government-issued photo ID.
Turnaround
1-3 business days
Availability
Our partner lab does not serve ND, RI, NY, NJ, MD or HI. Confirm availability for your location with the collection lab.

Before you go

  • Order your test before visiting a lab, then use the requisition form in your account.
  • Print the requisition form, or fax it to the lab directly from your account.
  • No scheduling is needed — visit the collection lab during its normal business hours.
  • A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
  • Bring a government-issued photo ID in case the lab requests it.
  • Results are posted to your secure account within 1–3 business days.

Requirements are summarized from our partner lab's published policies. Preparation and availability can change — confirm current instructions with the collection lab before your visit.

What this test is

Reverse T3 is a biologically inactive form of thyroid hormone produced when the body converts thyroxine (T4) in an alternative pathway. This test measures the amount of reverse T3 circulating in the blood. It is not a stand-alone diagnostic test but is interpreted with other thyroid hormone measurements.

What it measures

  • Reverse T3 — reflects the amount of this inactive thyroid hormone form in the blood
  • Total T3 — often measured alongside to assess active thyroid hormone levels
  • Free T4 — helps evaluate the main thyroid hormone produced by the thyroid gland
  • TSH — indicates how the pituitary gland is responding to thyroid hormone levels

What the test involves

A healthcare professional collects a small sample of blood, usually from a vein in your arm, using a standard blood draw. The sample is then sent to a laboratory for analysis.

Why it is often ordered

A clinician may order a reverse T3 test when thyroid test results are confusing or when a nonthyroidal illness is suspected. It is typically used to help evaluate whether symptoms or abnormal thyroid tests might be related to how the body is converting thyroid hormones.

Preparation

Preparation instructions can vary depending on the laboratory and the other tests being performed at the same time. Always follow the specific instructions provided by the collection lab or your healthcare provider.

How results are reported

Results are reported as a numeric value for reverse T3, and the laboratory will provide a reference range for comparison. Reference ranges can differ between laboratories because of differences in equipment, methods, and population, so your result should be interpreted using the range from the lab that performed the test.

Before you go

  • Whether any other tests will be drawn at the same time and if fasting is required.
  • The specific reference range used by the laboratory performing the test.
  • How and when you will receive your results.

Cities

Reverse T3 Test – rT3 Testing in Minnesota communities

Choose your city for local context and to order this test.

Minneapolis2,856,952Reverse T3 Test – rT3 TestingSt. Paul309,751Reverse T3 Test – rT3 TestingSt. Cloud123,569Reverse T3 Test – rT3 TestingRochester119,732Reverse T3 Test – rT3 TestingDuluth118,975Reverse T3 Test – rT3 TestingBloomington89,436Reverse T3 Test – rT3 TestingBrooklyn Park85,247Reverse T3 Test – rT3 TestingPlymouth80,034Reverse T3 Test – rT3 TestingWoodbury74,014Reverse T3 Test – rT3 TestingMaple Grove69,900Reverse T3 Test – rT3 TestingLakeville69,026Reverse T3 Test – rT3 TestingBlaine68,999Reverse T3 Test – rT3 TestingEagan68,205Reverse T3 Test – rT3 TestingEden Prairie64,048Reverse T3 Test – rT3 TestingBurnsville63,926Reverse T3 Test – rT3 TestingCoon Rapids63,269Reverse T3 Test – rT3 TestingApple Valley55,237Reverse T3 Test – rT3 TestingMinnetonka53,809Reverse T3 Test – rT3 TestingEdina53,059Reverse T3 Test – rT3 TestingSt. Louis Park49,539Reverse T3 Test – rT3 TestingMoorhead44,129Reverse T3 Test – rT3 TestingMankato43,938Reverse T3 Test – rT3 TestingShakopee43,396Reverse T3 Test – rT3 TestingMaplewood41,673Reverse T3 Test – rT3 TestingCottage Grove38,582Reverse T3 Test – rT3 TestingRichfield36,899Reverse T3 Test – rT3 TestingRoseville36,119Reverse T3 Test – rT3 TestingInver Grove Heights35,539Reverse T3 Test – rT3 TestingBrooklyn Center33,298Reverse T3 Test – rT3 TestingAndover32,471Reverse T3 Test – rT3 TestingSavage32,092Reverse T3 Test – rT3 TestingFridley29,422Reverse T3 Test – rT3 TestingOakdale28,019Reverse T3 Test – rT3 TestingChaska27,461Reverse T3 Test – rT3 TestingRamsey27,409Reverse T3 Test – rT3 TestingPrior Lake27,242Reverse T3 Test – rT3 TestingShoreview26,871Reverse T3 Test – rT3 TestingOwatonna26,366Reverse T3 Test – rT3 TestingWinona26,199Reverse T3 Test – rT3 TestingAustin26,030Reverse T3 Test – rT3 TestingChanhassen25,646Reverse T3 Test – rT3 TestingRosemount25,513Reverse T3 Test – rT3 TestingElk River25,467Reverse T3 Test – rT3 TestingWhite Bear Lake24,520Reverse T3 Test – rT3 TestingFaribault24,310Reverse T3 Test – rT3 TestingChamplin23,877Reverse T3 Test – rT3 TestingNew Brighton23,293Reverse T3 Test – rT3 TestingFarmington23,253Reverse T3 Test – rT3 TestingCrystal23,143Reverse T3 Test – rT3 TestingGolden Valley22,247Reverse T3 Test – rT3 TestingHastings22,063Reverse T3 Test – rT3 TestingNew Hope21,683Reverse T3 Test – rT3 TestingColumbia Heights21,612Reverse T3 Test – rT3 TestingLino Lakes21,180Reverse T3 Test – rT3 TestingWillmar20,823Reverse T3 Test – rT3 TestingSouth St. Paul20,637Reverse T3 Test – rT3 TestingWest St. Paul20,476Reverse T3 Test – rT3 TestingNorthfield20,374Reverse T3 Test – rT3 TestingForest Lake20,366Reverse T3 Test – rT3 TestingOtsego19,565Reverse T3 Test – rT3 Testing