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Midwest · Reverse T3 Test – rT3 Testing

Reverse T3 Test – rT3 Testing in Michigan

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 Michigan

Here is what you need before ordering and completing the Reverse T3 Test – rT3 Testing in MI. 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 Michigan communities

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

Detroit3,522,856Reverse T3 Test – rT3 TestingGrand Rapids604,311Reverse T3 Test – rT3 TestingAnn Arbor327,814Reverse T3 Test – rT3 TestingLansing312,829Reverse T3 Test – rT3 TestingFlint286,324Reverse T3 Test – rT3 TestingKalamazoo212,033Reverse T3 Test – rT3 TestingMuskegon164,136Reverse T3 Test – rT3 TestingWarren138,996Reverse T3 Test – rT3 TestingSterling Heights134,062Reverse T3 Test – rT3 TestingSouth Lyon128,071Reverse T3 Test – rT3 TestingSaginaw118,845Reverse T3 Test – rT3 TestingDearborn107,985Reverse T3 Test – rT3 TestingHolland100,202Reverse T3 Test – rT3 TestingLivonia95,294Reverse T3 Test – rT3 TestingJackson87,230Reverse T3 Test – rT3 TestingTroy86,912Reverse T3 Test – rT3 TestingPort Huron86,440Reverse T3 Test – rT3 TestingWestland84,961Reverse T3 Test – rT3 TestingFarmington Hills83,749Reverse T3 Test – rT3 TestingWyoming76,625Reverse T3 Test – rT3 TestingSouthfield76,196Reverse T3 Test – rT3 TestingRochester Hills75,990Reverse T3 Test – rT3 TestingBattle Creek75,608Reverse T3 Test – rT3 TestingBay City67,917Reverse T3 Test – rT3 TestingNovi65,369Reverse T3 Test – rT3 TestingTaylor63,071Reverse T3 Test – rT3 TestingDearborn Heights62,334Reverse T3 Test – rT3 TestingPontiac61,498Reverse T3 Test – rT3 TestingSt. Clair Shores59,046Reverse T3 Test – rT3 TestingRoyal Oak58,368Reverse T3 Test – rT3 TestingKentwood53,884Reverse T3 Test – rT3 TestingPortage48,767Reverse T3 Test – rT3 TestingRoseville47,692Reverse T3 Test – rT3 TestingEast Lansing47,427Reverse T3 Test – rT3 TestingMidland42,425Reverse T3 Test – rT3 TestingLincoln Park39,741Reverse T3 Test – rT3 TestingEastpointe34,148Reverse T3 Test – rT3 TestingSouthgate29,990Reverse T3 Test – rT3 TestingOak Park29,677Reverse T3 Test – rT3 TestingBurton29,532Reverse T3 Test – rT3 TestingMadison Heights28,719Reverse T3 Test – rT3 TestingAllen Park28,431Reverse T3 Test – rT3 TestingForest Hills28,327Reverse T3 Test – rT3 TestingHamtramck27,548Reverse T3 Test – rT3 TestingGarden City27,268Reverse T3 Test – rT3 TestingInkster25,849Reverse T3 Test – rT3 TestingHolt25,755Reverse T3 Test – rT3 TestingOkemos25,179Reverse T3 Test – rT3 TestingWalker25,149Reverse T3 Test – rT3 TestingNorton Shores25,040Reverse T3 Test – rT3 TestingWyandotte24,992Reverse T3 Test – rT3 TestingRomulus24,977Reverse T3 Test – rT3 TestingAuburn Hills24,202Reverse T3 Test – rT3 TestingAllendale23,999Reverse T3 Test – rT3 TestingWaverly23,328Reverse T3 Test – rT3 TestingMount Pleasant21,880Reverse T3 Test – rT3 TestingBirmingham21,728Reverse T3 Test – rT3 TestingAdrian20,674Reverse T3 Test – rT3 TestingMarquette20,561Reverse T3 Test – rT3 TestingYpsilanti20,448Reverse T3 Test – rT3 Testing