# Complement C3a

> This test measures C3a, a small protein fragment released when your immune system is active. It helps show if your body is currently reacting to inflammation or an immune trigger. Doctors use this information to see if symptoms are related to an overactive immune response rather than other causes. However, this test cannot pinpoint the specific disease causing the reaction or provide a diagnosis by itself.

- Labcorp code: 004220
- Category: [Immune Regulation](https://app.picardo.health/labs/tests/immune-regulation.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=004220&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.