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TestThyroid

Free T4

Measures the active, unbound thyroid hormone circulating in your blood. One quick draw, results usually in 1–2 business days.

$ 49.00All-in price
1Tests included

T4 (thyroxine) is the main hormone your thyroid produces. Free T4 measures the portion that's unbound and available for your body to use — a direct look at thyroid output that adds detail beyond a TSH alone, especially when investigating an over- or under-active thyroid.

Included Tests

Free T4
The active, unbound thyroid hormone.
Free T4
incl.in panel

What This Panel Measures

🦋
Thyroid output. Free T4 reflects the active hormone your thyroid is releasing right now.
⚖️
TSH context. Paired with TSH, it helps pinpoint whether a thyroid problem is over- or under-active.

Who Should Get This Panel

  • You have symptoms of an over- or under-active thyroid
  • You have an abnormal TSH and want more detail
  • You're on thyroid medication and monitoring your dose
  • You have a known thyroid condition

Conditions Screened

HypothyroidismHyperthyroidismThyroid dysfunction

Related Symptoms

FatigueWeight changesFeeling cold or hotHair thinningPalpitations

When to Get Tested

Any time; no fasting is required. If you take thyroid medication, testing at a consistent time relative to your dose makes results easier to compare. Free T4 is most useful alongside a TSH.

Understanding Your Results

Results post to your secure online account usually in 1–2 business days, with your value and the normal range. Free T4 is best read together with TSH: for example, a low Free T4 with a high TSH points to an underactive thyroid. Interpret medication-related results with your prescriber.

Frequently Asked Questions

Do I need to fast?
No fasting is required.
Should I also test TSH?
Usually yes — TSH plus Free T4 gives a much clearer picture of thyroid function than either test alone.
Is this billed to insurance?
No — you pay directly here, and nothing appears on your insurance record. Results go only to your secure account.

Pairs Well With — Same Blood Draw

TSH
The first-line thyroid screen.
+ Add
Thyroid Peroxidase Antibodies (TPO)
Checks for autoimmune thyroid disease.
+ Add
Complete Thyroid Panel
Full thyroid assessment in one draw.
+ Add
$ 49.00
✓ The price you see is the price you pay. No draw fees. No physician fees. No surprise bills. $ 49.00 is all-in.
Comparing prices? Some self-pay labs advertise a low number, then add ~$28 in "lab & physician fees" at checkout. We don't. What you see here is the whole cost.
⚡ We send your lab order electronically to the test center in 2–3 minutes. Nothing to print, nothing to bring — just walk in and sign in.
📍 Can you get tested nearby?

Test centers don’t accept payment — you pay securely here; the lab just does the draw.
⚡ Results 1–2 business days🧪 1 tests

What happens after you order?

  • 1Your lab order form & test code appear in your secure online account — with your test center’s address.
  • 2We send your lab requisition to the test center electronically.
  • 3Walk in & get tested — tests usually take 5 minutes or less.
📞 Need support? (866) 873-0879
$ 49.00all-in · no extra fees