# Complement, Total (CH50)

> This test measures the activity of the complement system, a group of proteins in your blood that helps your immune system fight infections. It helps show whether these proteins are working together properly or if they are being used up by chronic inflammation. Doctors often use this measurement to monitor autoimmune conditions like lupus or to check for missing immune system components. However, a normal result does not rule out all immune issues, as it does not measure the exact amount of every specific protein individually.

- Labcorp code: 001941
- Category: [Autoimmunity](https://app.picardo.health/labs/tests/autoimmunity.md)
- Price: shown at checkout, before payment.
- Blood draw: free at a Labcorp location, or $75.00 at home.
- Order link: https://app.picardo.health/labs/order?tests=001941&ref=assistant

## About ordering

A licensed physician reviews every order before any test is run, and results arrive in the person's Picardo account. Ordering is open to adults 18 and over in the US, except New York, New Jersey, Rhode Island, Pennsylvania, Maryland, Massachusetts, Hawaii and Maine. General health information, not medical advice.