Order Rheumatoid Factor (RF) Blood Test from JustLabs for $8 ($26 all-in for a single-test order: $8 + one $18 lab & physician order fee per order). Price includes lab processing at Quest Diagnostics. No insurance required.
Rheumatoid Factor is an autoantibody commonly elevated in rheumatoid arthritis. This test helps diagnose RA and assess disease severity, though RF can also be elevated in other conditions.
Rheumatoid Factor (RF) is an autoantibody—an antibody that mistakenly attacks your own body's tissues. In rheumatoid arthritis (RA), RF targets the Fc portion of IgG antibodies, forming immune complexes that contribute to joint inflammation and damage.
RF testing is one of the key blood tests used to help diagnose rheumatoid arthritis, typically alongside anti-CCP antibodies, inflammatory markers (ESR, CRP), and clinical examination. About 70-80% of people with RA test positive for RF.
However, RF is not specific to rheumatoid arthritis. It can be elevated in other autoimmune diseases (Sjogren's syndrome, lupus), chronic infections, and even in some healthy individuals, especially older adults. A positive RF alone doesn't diagnose RA—clinical symptoms and additional testing are essential.
Price
$8
All-in
$26
incl. $18 lab & physician fee
Results
2-3 business days
Fasting
Not Required
What's Measured
What This Test Measures
This test measures the concentration of rheumatoid factor antibodies in your blood, typically reported in IU/mL. Results are often categorized as negative (<14 IU/mL), low positive (14-39 IU/mL), moderate positive (40-59 IU/mL), or high positive (≥60 IU/mL). Higher levels often correlate with more severe disease.
Who Should Consider This Test
People with joint pain, swelling, or stiffness (especially in hands and feet), those with morning stiffness lasting over an hour, individuals with symmetric joint involvement, anyone with suspected autoimmune disease, and those with a family history of rheumatoid arthritis.
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
No fasting required. RF can be tested at any time. For RA diagnosis, RF is best interpreted alongside anti-CCP antibodies, ESR, and CRP, plus clinical examination by a rheumatologist.
No fasting needed. How to prepare for your blood test →
Understanding Your Results
Negative RF (<14 IU/mL) makes RA less likely but doesn't rule it out—20-30% of RA patients are "seronegative." Positive RF suggests RA is possible, but confirmatory testing and clinical evaluation are needed. Higher RF levels often correlate with more aggressive disease, joint damage risk, and extra-articular manifestations.
What to Expect
After placing your order, we send it straight to Quest Diagnostics — there is no consent form to sign and no partner email to wait for. Your requisition is usually ready to download from your dashboard within about an hour, and you can book your blood draw at any Quest Diagnostics location.
The blood draw typically takes just a few minutes. Results are usually available within 2-3 business days and will appear in your secure JustLabs dashboard.
Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.
How much does the RF test cost?
The RF test costs $8 at JustLabs — $26 all-in, since the $18 lab & physician order fee is charged once per order, however many tests you add. The price is fixed before your blood draw; no insurance or doctor visit needed.
| Option | Price | Order all-in | Notes |
|---|---|---|---|
| RF at JustLabsDrawn at Quest Diagnostics | $8 | $26 | Includes the one $18 fee, charged once per order |
Paying with an HSA or FSA? See which lab tests qualify
Frequently Asked Questions
Hospital cash price: $150–$300
$8
+ $18 order fee · $26 all-inOne $18 fee per order covers your Quest blood draw and the independent physician order, however many tests you add.
- Results in 2-3 business days
- No fasting required
- Physician order included
No insurance needed · HSA/FSA eligible
- Physician-ordered
- CLIA-certified Quest lab
- Drawn at Quest Diagnostics
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