Complement Components C3c and C4c Panel
Two core complement proteins that drop when autoimmune disease is actively consuming them.
Consider this test if:
- Diagnosed with lupus (SLE) and tracking disease activity or flares
- Investigating unexplained rashes, joint pain, kidney involvement, or signs of vasculitis
- Following an immune-complex condition where complement consumption is expected
- Recurrent or unusual infections that raise the question of complement deficiency
- Establishing a complement baseline before or during immunosuppressive treatment
- HSA/FSA eligible
- Results delivered to your dashboard · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. A routine serum sample is sufficient. If you are monitoring an autoimmune condition, drawing at consistent intervals makes trends easier to interpret, since both proteins also rise temporarily with acute infection or inflammation.
Video consult with your Care Team
A 1:1 call to discuss your health.
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What this test is for
Complement C3 and C4 are proteins of the immune system's complement cascade, which helps clear pathogens and immune complexes. Both fall when complement is being consumed faster than the body makes it, which is the pattern seen in active autoimmune disease. Low C3 and C4 together point to classical-pathway activation, while a low C3 with normal C4 points to the alternative pathway. The pairing is used most often to monitor disease activity in systemic lupus erythematosus (SLE) and in immune-complex vasculitis, where levels tend to fall during flares and recover as inflammation settles. Levels can also be low from inherited complement deficiency or rise nonspecifically as acute-phase reactants during infection or inflammation.
Biomarkers tested
Includes 2 biomarkers
- Specimen
- Serum or plasma
- Measures
- Mass concentration
- Specimen
- Serum or plasma
- Measures
- Mass concentration
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Fast, dashboard-delivered results
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
Mito Membership
$9 /mo
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Without membership
$0
pay as you go
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost — covering the lab and what it takes to run the service — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
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