📅 Last Updated: April 2026 | 🩺 Medically Reviewed by: Edward Salko, D.O., Medical Director | 🧪 Lab Partner: Labcorp
Also Known As
Thyroid Function Panel, Complete Thyroid Test, TSH Free T3 Free T4 Panel
What Is the Basic Thyroid Health Profile?
The Basic Thyroid Health Profile measures three essential thyroid markers — TSH (thyroid-stimulating hormone), Free T4 (thyroxine), and Free T3 (triiodothyronine) — in a single panel designed to give a complete picture of thyroid function and metabolism regulation.
Designed by Dr. J.E. Williams, this profile goes beyond a basic TSH-only test by including the active forms of both thyroid hormones. Your thyroid controls metabolism, energy, body temperature, heart rate, mood, and weight. When it’s underactive (hypothyroidism) or overactive (hyperthyroidism), the effects touch nearly every system in the body. Testing all three markers together provides a complete view that a TSH-only test cannot.
What Does This Panel Measure?
TSH (Thyroid-Stimulating Hormone) — Produced by the pituitary gland, TSH signals the thyroid to produce hormones. It’s the most sensitive early marker of thyroid dysfunction. High TSH = underactive thyroid; low TSH = overactive thyroid.
Free T4 (Free Thyroxine) — The primary hormone produced by the thyroid gland. “Free” T4 is the unbound, active form available to tissues. Low Free T4 with high TSH confirms hypothyroidism; elevated Free T4 with low TSH confirms hyperthyroidism.
Free T3 (Free Triiodothyronine) — The most biologically active thyroid hormone. T3 is largely converted from T4 in peripheral tissues. Some patients have normal TSH and T4 but poor T4-to-T3 conversion — a pattern that only shows up when Free T3 is measured, and one of the most common reasons people on levothyroxine still feel unwell.
Reference Ranges
| Marker | Normal Range | Low (Hypothyroid Signal) | High (Hyperthyroid Signal) |
|---|---|---|---|
| TSH | 0.4–4.0 mIU/L | Above 4.0 | Below 0.4 |
| Free T4 | 0.8–1.8 ng/dL | Below 0.8 | Above 1.8 |
| Free T3 | 2.3–4.2 pg/mL | Below 2.3 | Above 4.2 |
Reference ranges may vary slightly by laboratory. Many functional medicine providers target TSH of 1.0–2.5 mIU/L as optimal. Always review results with your healthcare provider.
What Conditions Can This Panel Detect?
| Result Pattern | Likely Indication |
|---|---|
| High TSH + Low Free T4 | Primary hypothyroidism |
| Low TSH + High Free T4 + High Free T3 | Hyperthyroidism / Graves’ disease |
| High TSH + Normal Free T4 | Subclinical hypothyroidism |
| Normal TSH + Low Free T3 | Poor T4-to-T3 conversion (common in levothyroxine patients) |
| Low TSH + Normal Free T4 | Subclinical hyperthyroidism |
Who Should Get This Test?
If you have symptoms of an underactive thyroid:
- Unexplained fatigue or low energy
- Unexplained weight gain or difficulty losing weight
- Constant cold sensitivity
- Brain fog, poor memory, or difficulty concentrating
- Hair thinning or hair loss
- Dry skin or brittle nails
- Depression or mood changes
- Constipation
- Irregular or heavy periods
- Elevated cholesterol despite healthy diet
If you have symptoms of an overactive thyroid:
- Rapid or irregular heartbeat
- Unexplained weight loss
- Heat intolerance or excessive sweating
- Anxiety, irritability, or tremors
- Difficulty sleeping
Higher-risk groups who should test regularly:
- Women over 35 — thyroid disorders are 5–8x more common in women
- Anyone with a family history of thyroid disease
- People with autoimmune conditions (Hashimoto’s, Type 1 diabetes, lupus, rheumatoid arthritis)
- Postpartum women — postpartum thyroiditis affects up to 10% of new mothers
- Anyone currently on levothyroxine or other thyroid hormone therapy
- People taking GLP-1 medications for weight loss — thyroid baseline is important before starting treatment
- Anyone with Type 2 diabetes or metabolic syndrome
Test Preparation
On thyroid medication (levothyroxine, Synthroid, Armour Thyroid, etc.): Get your blood drawn before taking your daily dose. Medication taken before the draw can temporarily elevate Free T4 and distort results.
Not on thyroid medication: No fasting required. No special preparation needed. Morning draws are preferred since TSH follows a slight daily rhythm — levels are highest in early morning.
Taking biotin supplements: Stop biotin (B7) at least 48 hours before your draw. High-dose biotin can interfere with thyroid immunoassays and produce falsely abnormal results.
How Much Does a Thyroid Health Profile Cost?
| Where You Get Tested | Typical Cost | Notes |
|---|---|---|
| Personalabs | $155 | Physician order included, all 3 markers |
| Doctor’s office visit + lab | $250–$450+ | Office copay + separate lab bill |
| Hospital outpatient lab | $400–$700+ | Facility fees apply |
| Endocrinologist visit | $500–$900+ | Specialist copay + lab |
HSA and FSA eligible. Thyroid testing qualifies as a reimbursable medical expense under most plans.
Where Can I Get a Thyroid Panel Near Me?
After ordering online, visit any of our 4,000+ partner patient service centers nationwide, including Labcorp locations.
Step 1: Order online — your physician-approved lab order is ready within 2–4 hours. Step 2: Find a lab near you using our Lab Locator. Step 3: Walk in for your blood draw — no appointment needed at most locations. Step 4: Get results in your secure Personalabs account within 24–48 hours.
Frequently Asked Questions: Basic Thyroid Health Profile
What is included in the Basic Thyroid Health Profile?
The Basic Thyroid Health Profile includes TSH (thyroid-stimulating hormone), Free T3 (active thyroid hormone), and Free T4 (inactive thyroid hormone). Together these three markers evaluate thyroid hormone production from the pituitary signal (TSH), through hormone output (Free T4), to active conversion (Free T3) — giving a complete picture that TSH alone cannot provide.
What is the difference between the Basic and Optimal Thyroid profiles?
The Basic Thyroid Profile includes TSH, Free T3, and Free T4 — covering production and conversion. The Optimal Thyroid Health Profile adds Reverse T3 (the inactive T3 blocker elevated under chronic stress) and TPO and Thyroglobulin antibodies (for Hashimoto’s detection). The Optimal Profile is recommended when autoimmune disease is suspected or symptoms persist despite normal basic results.
Who should order the Basic Thyroid Health Profile?
Anyone with fatigue, unexplained weight changes, hair thinning, brain fog, cold intolerance, constipation, or depression that may have a thyroid cause. Anyone on levothyroxine who still has symptoms despite normal TSH. Anyone who has only had TSH tested and wants the complete picture. Annual monitoring for anyone with non-autoimmune hypothyroidism on stable medication.
Do I need to fast for the Basic Thyroid Profile?
No fasting required. If you take thyroid medication draw blood before your morning dose for the most accurate baseline. Available through Personalabs — results in 24 to 48 hours. HSA and FSA eligible.
