Complement C4a
A complement split product that rises with inflammation, autoimmune activity, and immune-complex disease.
Consider this test if:
- Working up suspected antiphospholipid syndrome or another autoimmune, immune-complex condition
- Tracking inflammatory or complement activity in a known autoimmune disease
- Monitoring multiple sclerosis activity, where C4a can rise with relapse
- Investigating recurrent unexplained inflammation alongside other complement markers
- HSA/FSA eligible
- Typical results in 4-7 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. Because this test uses radioimmunoassay, no radioactive isotopes should be administered in the 48 hours before the draw. The sample needs special handling: blood is collected into a chilled EDTA tube with Futhan preservative, then separated and frozen promptly, so it must be drawn where that protocol can be followed. Pregnancy raises C4a and is worth noting on the requisition.
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What this test is for
Complement C4a is an anaphylatoxin, one of the small fragments (alongside C3a and C5a) released when the complement cascade activates as part of the immune response. It promotes inflammation by triggering histamine release from mast cells, increasing vascular permeability, and recruiting immune cells to sites of infection or tissue injury. Levels rise in conditions tied to complement activation and inflammation, including antiphospholipid syndrome, immune-complex and hypersensitivity diseases, and multiple sclerosis, where C4a tends to climb during relapse. Normal pregnancy also raises C4a, so results are read against clinical context rather than as a standalone finding. Because these split products exist only in trace amounts in healthy plasma and activate easily after the draw, this test depends on strict cold handling and a special preservative to keep the result accurate.
- Specimen
- Plasma
- Measures
- Mass concentration
What you'll learn
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Insights that connect the dots. A clinician reads your whole picture, not one result in isolation, connecting family history, past results, and lifestyle into clear next steps.
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Your personalized action plan. Nutrition, supplements, and training in one clinician-reviewed protocol, updated as your results change.
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Track your trends. Upload results from any lab and see each biomarker trend over time, so you know what is working.
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Never miss a recheck. Mito tells you what is worth retesting and when, then reminds you so nothing slips.
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 Typical results in 4-7 days
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.
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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. It is never a profit on the test itself. Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9 per month, and any applicable lab order or draw fee is itemized before you pay.
Where do I get tested?
Choose an available partner lab at checkout. If your cart contains multiple blood tests, Mito helps consolidate the eligible tests at one lab when possible. At-home kits and scans follow the collection or appointment process shown on their product page.
Is this eligible for HSA/FSA?
Yes. Eligible tests can be paid for with an HSA or FSA card at checkout.
When will I get my results?
Your results appear in your Mito dashboard after the laboratory completes processing. A clinician then reviews them before your analysis and personalized action plan are finalized. Timing varies by test, and specialty assays and at-home kits may take longer.
Do I need a physician's order?
No. Mito provides the laboratory order when one is required, so you do not need to arrange a separate physician visit before purchasing.
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