Quick Facts
- Sample: Blood serum via venipuncture
- Fasting: No fasting required
- Turn-around: 4-6 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Comprehensive thyroid evaluation - measures 6 key biomarkers including TSH, Free T3, Free T4, and Reverse T3
- Early detection - identifies thyroid dysfunction before symptoms become severe
- Stress response insights - Reverse T3 reveals how stress affects thyroid metabolism
- No doctor referral needed - convenient direct-to-consumer ordering and confidential online access
- Cost-effective monitoring - affordable alternative to comprehensive thyroid panels
Who Is This Test For?
- Individuals with thyroid symptoms - fatigue, weight changes, mood swings, irregular heart rate
- Those monitoring existing thyroid conditions - tracking treatment effectiveness
- People under chronic stress - assessing stress impact on thyroid hormone metabolism
- Health-conscious adults - proactive screening for metabolic and hormonal balance
- Anyone with family history - early detection of hereditary thyroid disorders
How It Works – Just 3 Steps
- Order online - no physician referral required, select convenient lab location
- Visit lab for blood draw - quick venipuncture at certified walk-in center
- Access results online - results available in 4-6 business days
FAQ
What hormones does this test measure? TSH, Free T3, Free T4, T3 Uptake, Free Thyroxine Index (T7), and Reverse T3 for comprehensive thyroid function assessment.
Can biotin supplements affect my results? Yes, stop biotin supplements at least 72 hours before testing to avoid interference with thyroid hormone assays (LabCorp 2023).
What is Reverse T3 and why is it important? Reverse T3 is an inactive form of T3 that increases during stress or illness, helping identify thyroid hormone metabolism issues.
How accurate is TSH testing for thyroid disorders? TSH testing is the most sensitive screening test for primary thyroid dysfunction with high specificity and sensitivity (AACE Guidelines 2012).
Do I need to fast before this test? No fasting is required unless specifically directed by your healthcare provider.
When will I get my results? Results are typically available within 4-6 business days and accessible online.
More Details
What is the purpose of this test?
This comprehensive thyroid panel evaluates thyroid gland function by measuring key hormones and their metabolism, including the inactive Reverse T3. It helps diagnose both underactive (hypothyroidism) and overactive (hyperthyroidism) thyroid conditions by assessing hormone production, regulation, and stress-related metabolism changes. The test provides detailed insights into thyroid hormone binding and conversion processes.
Who would benefit from this test?
Individuals experiencing symptoms of thyroid imbalance such as fatigue, weight changes, mood swings, or irregular heart rate would benefit most. Those with known thyroid disease monitoring treatment effectiveness, people under chronic stress assessing metabolic impact, and health-conscious individuals seeking preventive metabolic health insights should consider this panel. Anyone with family history of thyroid disorders or unexplained symptoms affecting energy, weight, or mood may find valuable insights.
When should I order the Thyroid #2 Essential Blood Test Panel plus Reverse T3?
Order this test when experiencing symptoms suggestive of thyroid dysfunction including fatigue, weight changes, chills, painful joints, dry skin, irregular heart rate, constipation, depression, anxiety, mood swings, or irregular menstrual periods. It's also valuable for ongoing monitoring of thyroid treatment effectiveness, investigating unexplained metabolic changes, or during periods of chronic stress that may affect thyroid hormone metabolism.
How do I interpret the results?
TSH:
- Normal Range: 0.4–4.0 mIU/L
- Typical Indication: Elevated suggests hypothyroidism; low suggests hyperthyroidism
Free T3:
- Normal Range: Lab-specific range
- Typical Indication: Reflects active thyroid hormone availability
Free T4:
- Normal Range: Lab-specific range
- Typical Indication: Primary thyroid hormone production indicator
Reverse T3:
- Normal Range: Low levels expected
- Typical Indication: Elevated may indicate stress-related metabolism issues
T3 Uptake:
- Normal Range: Lab-specific range
- Typical Indication: Measures thyroid hormone binding capacity
T7 (FTI):
- Normal Range: Lab-specific range
- Typical Indication: Calculated index of thyroid function
Abnormal results warrant physician consultation for proper diagnosis and treatment planning.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
Avoid biotin supplements for at least 72 hours before testing to prevent interference with thyroid hormone assays. No fasting is typically required unless otherwise directed. Inform the lab of any thyroid medications or supplements you're taking. Schedule your test for consistent timing if monitoring treatment, as thyroid hormone levels can vary throughout the day.
How often should I get tested?
- Initial screening: Once, then as clinically indicated
- Monitoring treatment: Every 6–8 weeks until stable
- Stable thyroid condition: Every 6–12 months
- Symptomatic changes: As needed when symptoms occur
- High-risk individuals: Annually or as recommended
Why early detection matters
Approximately 20 million Americans have some form of thyroid disease, with up to 60% remaining undiagnosed (American Thyroid Association 2020). Early detection of thyroid dysfunction reduces risks of cardiovascular disease and metabolic complications, improving quality of life and reducing healthcare costs. Untreated thyroid disorders can lead to serious complications including heart problems, osteoporosis, and mental health issues.
Related tests you may consider
Thyroid #3 Extreme Blood Test Panel plus Reverse T3 - Provides a detailed evaluation of thyroid function and detects the number of specific thyroid antibodies in the blood of individuals showcasing signs of thyroid disorder.
Thyroid #4 Comprehensive Blood Test Panel - Checks several important hormones, antibodies, and proteins to give a full picture of how well your thyroid is working, helping detect issues like thyroid disorders and autoimmune diseases.
Thyroid Antibodies Panel Blood Test - Detects and measures the number of specific thyroid antibodies in the blood to screen for thyroid disorders.
