All markers › Thyroid
Free T4
The thyroid's main storage hormone, available to the body.
Dr. Sorrell's optimal rangeRead alongside measured resting metabolic rateFrom the Sorrell MD Lab Decoder. Optimal ranges are stricter than the "normal" range printed on a lab report.
Who includes it, and what it costs
| Provider | Included / price | Checked |
|---|---|---|
| Function Health | ✓ included | 2026-10-16 |
| Superpower | not listed | 2026-10-16 |
| Jinfiniti AgingSOS Cellular Essentials | — | — |
| Quest (questhealth.com) | $149 Comprehensive Thyroid Test Panel (TSH, FT3, FT4, 2 antibodies) | 2026-10-16 |
| Labcorp OnDemand | — | — |
| Walk-In Lab | $39 Thyroxine (T4) Free Direct Serum Test | 2026-10-16 |
| Ulta Lab Tests | $25.95 T4 Free Test | 2026-10-16 |
| Mito Health | $5.52 non-member price; member $3.94 | 2026-10-16 |
| Rythm Health | ✓ included | 2026-10-16 |
| SiPhox Health | — | — |
| Everlywell | — | — |
| LetsGetChecked | — | — |
Memberships (Function, Superpower) and Jinfiniti's panel cover many markers for one price. See the home page. Quest and Walk-In Lab add a physician fee of about $6 per order.