T3 Reverse, LC/MS/MS
Quest Diagnostics
Sample type: Serum
Requires fasting: No
Phlebotomy required
Details
This test measures the levels of 3,3',5'-Triiodothyronine (reverse T3, rT3) in the blood. Reverse T3 is a version of the thyroid hormone that is not active in the body.
- Reverse T3
Estimated days for results: Results should be available in 2 - 5 business days after the sample is collected
Details
T3 Reverse, LC/MS/MS - This test measures the levels of 3,3',5'-Triiodothyronine (reverse T3, rT3) in the blood. Reverse T3 is a version of the thyroid hormone that is not active in the body. It's produced from thyroxine (T4), another thyroid hormone. Unlike its counterpart T3, reverse T3 doesn't affect your metabolism. This test is important for understanding thyroid health, especially in conditions where the body is under stress, such as illness, surgery, or malnutrition, which can affect thyroid hormone levels.
What patients is this test right for?
This test may be recommended for individuals experiencing symptoms or conditions that could affect thyroid function, including:
- Fasting or malnutrition
- Poorly controlled diabetes mellitus
- Recent trauma or surgery
- Systemic illness
What type of sample is required for this test?
0.5 mL serum. A blood draw is necessary.
3–5 business days
8-25 ng/dL
Blood Draw Options with Fullscript
Fullscript offers several convenient phlebotomy options to complete your lab testing:
Quest Diagnostics Patient Service Centers (PSC)
- Location: Visit a nearby Quest Diagnostics Patient Service Center.
- Cost: $10 sample collection fee (paid during lab order checkout).
- Scheduling: Schedule your appointment here. Appointments are recommended to reduce wait times. Walk-ins are accepted, but may experience delays. Aim to arrive 10 minutes before your appointment.
- Collection Instructions:
- Bring a valid ID.
- Bring your digital or printed requisition form, available in the Labs tab of your Fullscript account.
- Check-in: Scan the QR code from your confirmation email or follow kiosk instructions.
- More Info: Quest Diagnostics blood draw guide
Getlabs Mobile Phlebotomy
- Location: Sample collection at your home or office.
- Cost: $85 sample collection fee (paid during lab order checkout).
- Availability: Available in most locations – enter your ZIP code during checkout to confirm.
- Scheduling: Schedule your appointment here through your Fullscript account.
- Collection Instructions:
- Have your digital or printed requisition form and valid ID ready.
- Your phlebotomist will contact you by phone to coordinate arrival.
- More Info: Getlabs blood draw guide
Specimen
- Preferred Specimen(s): 0.5 mL serum
- Alternative: NA
- Minimum Volume: 0.3 mL
- Collection Instructions: NA
Storage and shipping instructions
- Transport Container: Transport tube
- Transport Temperature: Room Temperature
- Specimen Stability:
- Room temperature: 7 days
- Refrigerated: 7 days
- Frozen: 30 days
- Reject Criteria:
- Unseparated serum (>48 hours on clot) • Serum in Serum separator tube (SST) not separated from the gel within 24 hours
State restrictions:
Patient can't order this test if they are located in Hawaii, Puerto Rico, New Jersey, New York, or Rhode Island
