T3 Free

The T3 Free test measures the amount of "free" triiodothyronine in your blood. T3 is the most active form of thyroid hormone and is responsible for regulating your body’s temperature, heart rate, and metabolism. While T4 is produced in higher quantities, T3 is the hormone that actually does most of the work at the cellular level. Measuring the "free" version ensures we are seeing the hormone that is active and ready to use.

What This Test Covers

• Free Triiodothyronine (T3): Measures the active, unbound hormone responsible for energy and metabolic function.

• Conversion Efficiency: Helps determine if your body is successfully converting T4 into the more active T3 hormone.

Why Order This Test?

• Hyperthyroidism Diagnosis: Often used to confirm an overactive thyroid, as T3 levels frequently rise before T4 levels do.

• Unexplained Weight Changes: A key test for those struggling with rapid weight loss or an inability to gain weight despite a normal diet.

• Heart Palpitations and Anxiety: Helps determine if physical symptoms of "jitters," rapid heart rate, or heat intolerance are hormone-related.

• Thyroid Medication Adjustment: Essential for patients taking Liothyronine (Cytomel) or natural desiccated thyroid to ensure levels are in the therapeutic range.

• Complete Thyroid Picture: Provides the final piece of the puzzle when TSH and T4 results don't fully explain your symptoms.

Fast and Private Results

• Preparation: No fasting is required for this test.

• Turnaround Time: Results are typically available within 24 to 48 hours.

• Confidential: Your results are delivered securely to your private portal and are not shared with insurance providers.