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Complement C3 Blood Test

* This is not a home test kit. You will need to visit a local lab for testing.

Also Known As

Complement Activity C3, Complement Antigen

The Purpose of a C3 Complement Blood Test

Your immune system is powered by complement proteins so it can effectively fight invading germs. If your levels of complement proteins are too high or too low, however, that could indicate an autoimmune disorder such as celiac disease, lupus, or arthritis, or some sort of infection. A C3 blood test can help pinpoint potential health issues so you can get the care and treatment you need to manage your condition.

Complement C3, Serum (351)
Complement C3, Serum (006452)

What Does the C3 Test Measure?

This test tells you how much C3 protein is in your blood. (There are nine important complement proteins in total; this test only measures C3, but you can also choose a Complement Total (CH50) blood test that measures them all at once.)

Who Should Take a C3 Blood Test?

You may want to take a C3 test if you are experiencing symptoms associated with various autoimmune disorders. Your doctor may also recommend this test if you are being treated for an autoimmune condition, as a way of monitoring your progress.

C3 Lab Test Preparation

You don’t need to do anything special to prepare for the C3 complement blood test.

C3C Blood Test Results

Your test results may be measured in milligrams per deciliter (mg/dL) or grams per liter (g/L). The ideal C3 range is generally 75 to 175 mg/dL) or 0.75 to 1.75 (g/L). Kidney disease, lupus, and infection are just some of the issues associated with low C3 levels, while ulcerative colitis and leukemia are linked to high levels. If your levels fall outside the normal ranges, you may need to get follow-up tests for celiac diseaserheumatoid arthritis, or other autoimmune diseases. If you need help determining your next steps, schedule a telehealth appointment with one of our board-certified physicians.

Where Can I Get a Complement C3 Blood Test Near Me?

With more than 400 tests to choose from online, you can get the answers you need to guide your healthcare decisions. It’s easy to get a C3 test with Personalabs:

Step 1: Find the test you want, purchase it, and download the lab order that comes with the test. (A doctor’s approval may not be necessary for purchasing the test, depending on the state where you live.)

Step 2: Schedule the appointment for the blood draw at a Labcorp or Quest Diagnostics facility. We have more than 4,000 labs we’re partnered with across the country, so you use our locator tool to find the lab closest to you.

Step 3: Bring the test order to the lab when you have your blood drawn.

Step 4: Review your results. You can usually find them in your confidential Personalabs account within 2 to 10 business days after your test date. If  you need the results by a specific date, we can work with your lab to meet that turnaround time. Just contact us with this request or if you have other questions about the testing process. Our knowledgeable team is ready to help you.

Personalabs puts the power in your hands to make informed healthcare choices. Browse our comprehensive range of lab tests to get started.

Additional information


LabCorp, Quest

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Order Your Test

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Generate & Print Out Lab Order

Our physician network will approve your order within 2-4hrs.



Visit the Lab

The test price decides which lab you will visit: Quest or Labcorp. Find a location in your area.



Get Your Results

Results can be provided in as little as 24-48 hrs. For more complex tests, please contact us for turn around times.


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