# Thyroxine (T4)

> This test measures the total amount of thyroxine (T4), a hormone produced by your thyroid gland that controls how your body uses energy. It helps show whether your thyroid is overactive or underactive, which is often checked when patients experience fatigue or unexplained weight changes.

- Labcorp code: 001149
- Category: [Thyroid](https://picardo.health/labs/tests/thyroid.md)
- Sample: blood
- Labcorp turnaround: within 1 day
- 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=001149&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.