# 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.

- Labcorp code: 001941
- Category: [Autoimmunity](https://picardo.health/labs/tests/autoimmunity.md)
- Sample: blood
- Labcorp turnaround: 2–4 days
- Collection: free at a Labcorp location, or $75.00 at home.
- Without a doctor: yes. People order it themselves, with no doctor's visit or referral.
- Price: shown on the review page its order link opens. Opening it orders nothing.
- Order link: https://app.picardo.health/labs/order?tests=001941&ref=assistant

## About ordering

People order for themselves, with no doctor's visit or referral, and results arrive in their 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.