Also known as: IL-6 Blood Test, Interleukin 6 Test, IL6 Test
CPT code: 83520the billing code Quest, Labcorp and hospital labs all use for this test
The short answer
Interleukin-6 (IL-6) Test measures Interleukin-6 (IL-6) from a standard blood draw. At TestWell it costs $39.99 plus a $6 lab processing fee, needs no fasting, and results post in 3–5 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Quest or Labcorp.
TestWell Price
$39.99
+ $6 lab processing fee
Interleukin-6 (IL-6) is a cytokine — a chemical messenger released by immune cells, fat tissue, and muscle — that tells the liver to make C-reactive protein and drives fever and the acute-phase response. It rises within hours of an infection, injury, or flare of an inflammatory disease, often before CRP does, and it is chronically a little high in obesity, insulin resistance, chronic kidney disease, and smoking. Clinicians measure it to follow inflammatory activity in rheumatoid arthritis and other autoimmune conditions, to assess severity in serious infections, and in research on ageing and cardiovascular risk. Results are reported in pg/mL with the laboratory's reference range; most healthy adults are in the low single digits. Because IL-6 moves fast, one raised value usually means something recent — a cold, a hard workout the day before, poor sleep — and is best repeated when you are well before drawing conclusions. It does not diagnose a specific disease on its own.
Inflammation and autoimmune biomarkers help identify systemic inflammation, suspected autoimmune disease, and disease activity in known autoimmune conditions.
Anyone with unexplained joint pain, rashes, fatigue, or recurrent fevers; patients with known autoimmune disease monitoring flares; or individuals with strong family history of autoimmune conditions.
Sample Type
Blood draw
Fasting
Not required
Results In
3–5 business days · typical; varies by lab and draw day
Performed At
Quest or Labcorp
1 biomarker tested
Your Interleukin-6 (IL-6) Test results will include values for each of the 1 biomarker tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 3–5 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you. Already have results? Analyze them with your AI assistant against our physician-reviewed ranges.
No fasting required. Avoid strenuous exercise for 24 hours before the draw and, if you can, schedule it when you are not acutely ill — both raise IL-6 temporarily. A morning draw is easiest to compare over time.
TestWell orders the same Interleukin-6 (IL-6) Test the labs run for doctors' offices, so you can walk into any of these labs with our requisition — no doctor's visit, a licensed physician authorizes the order, and most patient service centers take walk-ins. The table shows each lab's own test code, the name printed on the requisition, what the lab charges on its own consumer site, and the price through TestWell at that lab (plus one $6 fee per order).
| Lab | Test code | On the requisition | Lab's own site | Through TestWell |
|---|---|---|---|---|
| Quest Diagnostics | — | “Interleukin-6 (IL-6) Test” | not sold direct | $99.99 + $6 |
| Labcorp | — | “Interleukin-6 (IL-6) Test” | not sold direct | $39.99 + $6 |
You choose the lab at checkout; the requisition is written for that lab and arrives by email within minutes. New York and New Jersey orders draw at BioReference. Lab-direct prices are read from the labs' public pages and re-checked regularly.
Where to get it near you: patient service centers by state and city · search by ZIP code
An Interleukin-6 (IL-6) Test costs $39.99 at TestWell — $45.99 all-in, since the $6 lab processing fee is charged once per order and there is no draw or physician fee. Hospital outpatient labs typically bill around $180.00 self-pay. With insurance you pay your plan's negotiated rate against your deductible; TestWell's price is fixed before the draw and HSA/FSA-eligible.
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Quest or Labcorp) | $39.99 | $45.99 | Includes the one $6 lab processing fee, charged once per order |
| TestWell (drawn at BioReference — New York & New Jersey) | $69.99 | $75.99 | New York and New Jersey orders route to BioReference; Quest Health and Labcorp OnDemand don't take self-ordered draws in those states |
| Hospital outpatient lab, self-pay (typical) | $180.00 | $180.00 | Reference figure; hospital charges vary widely by facility and are often higher |
Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Compare more: Quest Diagnostics price list · Labcorp price list · Quest vs Labcorp · Lab test price checker
Most Interleukin-6 (IL-6) Test results are available in 3–5 business days after your specimen arrives at the lab. You'll get an email the moment results are ready, with everything viewable in your TestWell portal.
Blood draw. A standard venous blood draw, collected at any Quest, Labcorp or BioReference patient service center — walk in with the requisition we email you, no appointment needed at most locations.
On TestWell, the Interleukin-6 (IL-6) Test is $39.99. Walk-in hospital labs typically bill $180 or more without insurance. Insurance is not required — pay one all-in price.
No fasting required for the Interleukin-6 (IL-6) Test. No fasting required. Avoid strenuous exercise for 24 hours before the draw and, if you can, schedule it when you are not acutely ill — both raise IL-6 temporarily. A morning draw is easiest to compare over time.
The Interleukin-6 (IL-6) Test is available at Quest and Labcorp patient service centers nationwide. Order online at TestWell, pick your preferred lab, and we'll generate a digital requisition for the location closest to you.
CPT 83520. That is the billing code Quest, Labcorp and hospital laboratories all use for an Interleukin-6 (IL-6) Test, so it is the number to match on an explanation of benefits, a doctor's order or a price list — the same code, the same test, whichever lab draws it. You do not need the code to order: TestWell sells the Interleukin-6 (IL-6) Test for $39.99 with the physician order included, no insurance required, and results in 3–5 business days.
Medically reviewed by Youmna DiStefano, MD · Last reviewed October 2026
TestWell Price
$39.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
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