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South · Reverse T3 Test – rT3 Testing

Reverse T3 Test – rT3 Testing in Oklahoma

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 Oklahoma

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

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

Oklahoma City994,284Reverse T3 Test – rT3 TestingTulsa715,983Reverse T3 Test – rT3 TestingNorman125,745Reverse T3 Test – rT3 TestingBroken Arrow112,751Reverse T3 Test – rT3 TestingEdmond93,522Reverse T3 Test – rT3 TestingLawton91,247Reverse T3 Test – rT3 TestingMoore62,633Reverse T3 Test – rT3 TestingMidwest City58,146Reverse T3 Test – rT3 TestingEnid51,129Reverse T3 Test – rT3 TestingStillwater48,055Reverse T3 Test – rT3 TestingOwasso37,559Reverse T3 Test – rT3 TestingMuskogee37,214Reverse T3 Test – rT3 TestingBartlesville37,074Reverse T3 Test – rT3 TestingShawnee31,237Reverse T3 Test – rT3 TestingBixby28,091Reverse T3 Test – rT3 TestingJenks25,210Reverse T3 Test – rT3 TestingArdmore24,829Reverse T3 Test – rT3 TestingPonca City24,499Reverse T3 Test – rT3 TestingYukon23,697Reverse T3 Test – rT3 TestingDuncan22,664Reverse T3 Test – rT3 TestingSapulpa21,853Reverse T3 Test – rT3 TestingDel City21,778Reverse T3 Test – rT3 TestingBethany20,542Reverse T3 Test – rT3 TestingSand Springs19,935Reverse T3 Test – rT3 TestingMustang19,847Reverse T3 Test – rT3 TestingClaremore19,173Reverse T3 Test – rT3 TestingAltus18,825Reverse T3 Test – rT3 TestingDurant18,358Reverse T3 Test – rT3 TestingMcAlester18,225Reverse T3 Test – rT3 TestingEl Reno17,164Reverse T3 Test – rT3 TestingAda16,804Reverse T3 Test – rT3 TestingTahlequah16,213Reverse T3 Test – rT3 TestingChickasha15,655Reverse T3 Test – rT3 TestingGlenpool13,446Reverse T3 Test – rT3 TestingMiami12,997Reverse T3 Test – rT3 TestingGuymon12,804Reverse T3 Test – rT3 TestingWoodward12,246Reverse T3 Test – rT3 TestingChoctaw12,130Reverse T3 Test – rT3 TestingWeatherford12,034Reverse T3 Test – rT3 TestingElk City11,743Reverse T3 Test – rT3 TestingOkmulgee11,330Reverse T3 Test – rT3 TestingNewcastle10,970Reverse T3 Test – rT3 TestingGuthrie10,767Reverse T3 Test – rT3 TestingWarr Acres10,443Reverse T3 Test – rT3 TestingCoweta9,696Reverse T3 Test – rT3 TestingThe Village9,510Reverse T3 Test – rT3 TestingPryor Creek9,439Reverse T3 Test – rT3 TestingPoteau8,741Reverse T3 Test – rT3 TestingClinton8,612Reverse T3 Test – rT3 TestingBlanchard8,511Reverse T3 Test – rT3 TestingSallisaw8,503Reverse T3 Test – rT3 TestingSkiatook8,396Reverse T3 Test – rT3 TestingCushing8,201Reverse T3 Test – rT3 TestingCatoosa7,821Reverse T3 Test – rT3 TestingCollinsville7,765Reverse T3 Test – rT3 TestingWagoner7,694Reverse T3 Test – rT3 TestingTuttle7,412Reverse T3 Test – rT3 TestingPiedmont7,306Reverse T3 Test – rT3 TestingSeminole7,131Reverse T3 Test – rT3 TestingNoble7,078Reverse T3 Test – rT3 Testing