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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