Advanced Thyroid Panel — Full Functional Thyroid Assessment
What Is the Advanced Thyroid Panel?
The advanced thyroid panel is a comprehensive Quest Diagnostics blood test that measures eight key markers of thyroid function:
TSH
Free T3
Free T4,
Total T3,
Total T4,
Reverse T3,
Thyroid Peroxidase antibodies (TPO)
Thyroglobulin antibodies (TgAb).
Most conventional thyroid screenings only test TSH and sometimes Free T4. That misses the full picture. By the time TSH alone is out of range, dysfunction has usually been building for years.
This panel is the standard functional medicine workup for anyone investigating chronic fatigue, unexplained weight changes, hair thinning, brain fog, low body temperature, or autoimmune symptoms. It checks whether your thyroid is producing hormone, whether your body is converting that hormone into its active form, and whether your immune system is attacking the gland. Run through Quest Diagnostics with sample collection at one of their nationwide Patient Service Centers.
What Symptoms Does This Test Help Address?
Chronic fatigue, especially morning fatigue and afternoon energy crashes
Unexplained weight gain or stubborn inability to lose weight
Hair thinning, hair loss, or loss of the outer third of the eyebrows
Cold intolerance, cold hands and feet
Brain fog, difficulty concentrating, slow thinking
Dry skin, brittle nails
Constipation
Irregular or heavy periods, fertility issues, postpartum mood changes
Anxiety, heart palpitations, or feeling wired but tired
Depression, mood swings, low motivation
Low libido
Family history of Hashimoto's, Graves', or autoimmune disease
Who Is This Test For?
Anyone who has been told their thyroid is normal based on TSH alone but still has symptoms
Women in perimenopause, postpartum, or experiencing hormonal shifts
Clients with diagnosed Hashimoto's or Graves' disease tracking antibody trends
People on thyroid medication who want a complete picture of how their dose is working
Anyone with a family history of autoimmune thyroid disease
Clients investigating autoimmunity, chronic fatigue, or unexplained weight changes
Test Details
Lab: Quest Diagnostics
Sample type: Serum (blood draw, phlebotomy required)
Fasting required: No (hydrate before your draw)
Collection method: Blood draw at any Quest Diagnostics Patient Service Center (PSC) or via Getlabs mobile phlebotomy at home or office
Average processing time: 3 to 5 business days from sample receipt
Biomarkers Tested (8 Total)
This panel measures eight biomarkers covering thyroid hormone production, conversion, total circulating pool, and autoimmunity:
Thyroid-Stimulating Hormone (TSH): The pituitary signal that tells the thyroid to make hormone. The standard first-line screening marker.
Free T4 (FT4): The unbound, biologically active form of T4, the storage hormone your body converts to T3. Direct measurement, not a calculated index.
Total T4: The full circulating pool of T4 hormone, including protein-bound and free forms. Useful for tracking total thyroid output.
Free T3 (FT3): The unbound, active form of T3, the most metabolically active thyroid hormone. The marker most correlated with how you actually feel.
Total T3: The full circulating T3 pool. Helps distinguish between thyroid production issues and conversion issues.
Reverse T3 (RT3): An inactive form of T3 produced when the body is under stress or inflammation. Elevated RT3 can cause hypothyroid symptoms even when other markers look normal.
Thyroid Peroxidase Antibodies (TPO): The primary autoimmune marker for Hashimoto's. Elevated TPO is one of the earliest signs of autoimmune thyroid disease, often appearing years before TSH goes out of range.
Thyroglobulin Antibodies (TgAb): A second autoimmune marker that helps identify Hashimoto's thyroiditis, especially in cases where TPO is negative.
Collection Instructions
This is a blood draw test. After purchase, your Cync Health practitioner orders the panel through Fullscript and you receive a requisition form in your account. You then schedule your blood draw using one of two options:
Quest Diagnostics Patient Service Center (PSC): Visit a nearby Quest location. There are thousands of PSCs nationwide. $10 collection fee, paid at the time you order through Fullscript. Schedule online or walk in (appointments recommended to avoid wait times).
Getlabs mobile phlebotomy: A phlebotomist comes to your home or office. $85 collection fee paid at Fullscript checkout.
Important: the $199 test price does not include the phlebotomy collection fee. The Quest PSC fee ($10) or Getlabs mobile fee ($85, should you choose this service) is paid separately at the time you schedule your labs.
Before your draw:
Hydrate well
No fasting required
Discontinue any biotin supplements at least 8 hours before your draw. If you take high-dose biotin (above 5mg daily), stop at least 72 hours before. Biotin interferes with thyroid lab accuracy.
Bring a valid ID and your printed or digital requisition form
Availability and State Restrictions
This panel is not available for ordering in Hawaii, Rhode Island, New Jersey, New York, or Puerto Rico due to state lab regulations.
Frequently Asked Questions
What's included in an advanced thyroid panel? This panel measures eight markers through Quest Diagnostics: TSH, Free T3, Free T4, Total T3, Total T4, Reverse T3, TPO antibodies, and Thyroglobulin antibodies. Together these assess thyroid hormone production, conversion, total circulation, and autoimmunity.
Why is TSH alone not enough to assess thyroid function? TSH is a pituitary signal, not a direct measurement of thyroid hormone. People can have normal TSH while running low Free T3 or elevated antibodies signaling autoimmune disease. A full panel reveals dysfunction TSH misses.
What does Reverse T3 measure? Reverse T3 is an inactive form of T3 the body produces under stress, illness, or inflammation. High RT3 can block the active T3 from doing its job, causing hypothyroid symptoms even when standard labs look normal.
Who should order a complete thyroid panel? Anyone with thyroid symptoms who has been told their bloodwork is normal, anyone on thyroid medication, anyone with a personal or family history of autoimmune disease, and anyone investigating chronic fatigue, weight changes, hair loss, or mood symptoms.
Do I need to fast for a thyroid panel? No fasting required. Hydrate before your draw. The most important prep is stopping biotin supplements: at least 8 hours before the draw for regular doses, 72 hours for high-dose biotin.
How long do thyroid panel results take? Results return in 3 to 5 business days from when the lab receives your sample. You will then receive your results as soon as they are received from the lab.
*These statements have not been evaluated by the Food and Drug Administration. This test is not intended to diagnose, treat, cure, or prevent any disease. Results should be reviewed with a qualified healthcare practitioner.
