# Protein S, Free

> This test measures the amount of free Protein S in your blood, a protein that helps prevent excessive blood clotting. It helps show whether you have enough active Protein S to stop clots from forming when they are not needed. Doctors use this measurement to evaluate the cause of unexplained blood clots or to check for an inherited clotting disorder. However, this test cannot diagnose a current blood clot or identify other reasons for clotting problems on its own.

- Labcorp code: 164519
- Category: [Heart & Metabolic](https://app.picardo.health/labs/tests/heart-metabolic.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=164519&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.