📅 Last Updated: April 2026 | 🩺 Medically Reviewed by: Edward Salko, D.O., Medical Director | 🧪 Lab Partner: Labcorp
Also Known As
Thyroid Function Panel, Thyroid Profile with TSH, Thyroid Blood Test
What Is a Thyroid Panel with TSH?
A thyroid panel with TSH is a comprehensive blood test that evaluates how well your thyroid gland is functioning. It measures three key markers — TSH (thyroid-stimulating hormone), Total T4 (thyroxine), and T3 Uptake — to screen for thyroid disorders including hypothyroidism, hyperthyroidism, Hashimoto’s disease, and Graves’ disease.
According to the American Thyroid Association, thyroid disorders affect an estimated 20 million Americans. The thyroid is a small butterfly-shaped gland in your neck that regulates metabolism, energy, body temperature, heart rate, and mood. Even minor imbalances in thyroid hormone levels can cause wide-ranging symptoms that affect your quality of life. This panel gives you and your healthcare provider a clear picture of your thyroid status without a doctor’s visit or insurance.
📅 Last Updated: April 2026 | 🩺 Medically Reviewed by: Edward Salko, D.O., Medical Director | 🧪 Lab Partner: Labcorp
What Does the Thyroid Panel Measure?
| Marker | What It Measures |
|---|---|
| TSH | Pituitary signal telling the thyroid to produce hormones; the primary screening marker |
| Total T4 (Thyroxine) | Main hormone produced by the thyroid gland |
| T3 Uptake | Reflects how much T3 is available and bound to carrier proteins |
Together these markers help identify whether your thyroid is underactive (hypothyroidism), overactive (hyperthyroidism), or functioning normally.
Thyroid Panel Normal Ranges — What Each Marker Means
| Marker | Normal Range | Low Indicates | High Indicates |
|—|—|—|—|
| TSH | 0.4–4.0 mIU/L | Hyperthyroidism (overactive) | Hypothyroidism (underactive) |
| Free T4 | 0.8–1.8 ng/dL | Hypothyroidism, pituitary issue | Hyperthyroidism, excess medication |
| Free T3 | 2.3–4.1 pg/mL | T3 conversion disorder | Hyperthyroidism |
| Total T4 | 5.0–12.0 mcg/dL | Hypothyroidism | Hyperthyroidism |
| T3 Uptake | 24–39% | Elevated TBG, pregnancy | Low TBG, androgens |
Why TSH Alone Is Not Enough
Most doctors order only TSH when screening for thyroid disease. But TSH alone misses a critical subset of thyroid dysfunction — people with normal TSH but low Free T3.
Here’s why it happens: Your thyroid produces primarily T4 — an inactive precursor hormone. T4 is converted to the active T3 hormone by enzymes in peripheral tissues. This conversion can be impaired by chronic stress, selenium deficiency, inflammation, and insulin resistance — leaving you with normal TSH and normal T4 but functionally low T3.
Symptoms of low T3 with normal TSH include persistent fatigue despite normal thyroid labs, inability to lose weight, brain fog, cold intolerance, hair thinning, constipation, and depression. These patients are often told “your thyroid is fine” — but a full panel including Free T3 tells the real story.
The complete thyroid panel includes TSH, Free T4, Free T3, and Total T4 — giving a comprehensive picture of thyroid hormone production AND conversion that TSH alone cannot provide.
Who benefits most from a full thyroid panel rather than TSH alone: anyone with persistent hypothyroid symptoms despite normal TSH, anyone on thyroid medication being optimized, women with fertility challenges, anyone with Hashimoto’s monitoring treatment response, and anyone considering T3-containing thyroid medications.
Reviewed by Edward Salko, D.O., Medical Director, Personalabs
Who Should Get a Thyroid Panel with TSH?
Consider this test if you experience any of the following:
Symptoms of hypothyroidism (underactive thyroid):
- Persistent fatigue or low energy
- Unexplained weight gain
- Cold intolerance
- Depression or brain fog
- Dry skin, brittle nails, or hair loss
- Constipation
- Slow heart rate
Symptoms of hyperthyroidism (overactive thyroid):
- Unexplained weight loss
- Rapid or irregular heartbeat
- Anxiety or nervousness
- Heat intolerance and excessive sweating
- Frequent bowel movements
- Tremors or muscle weakness
Also recommended for:
- Anyone with a family history of thyroid disease
- Women over 35 (thyroid disorders are significantly more common in women)
- People with autoimmune conditions
- Patients currently being treated for thyroid disorders who need monitoring
- Anyone experiencing unexplained fatigue, weight changes, or mood shifts
Thyroid Panel Reference Ranges
| Marker | Normal Range |
|---|---|
| TSH | 0.4 – 4.0 mIU/L |
| Total T4 | 4.5 – 12.5 mcg/dL |
| T3 Uptake | 24 – 39% |
High TSH + Low T4 = hypothyroidism (underactive thyroid) Low TSH + High T4 = hyperthyroidism (overactive thyroid)
Reference ranges may vary by laboratory. Always review results with a qualified healthcare provider. For a more detailed picture, consider our Optimal Thyroid Panel.
Test Preparation
No fasting is required. If you are currently taking thyroid medication (such as levothyroxine), have your blood drawn before your morning dose for the most accurate TSH reading. Otherwise, no special preparation is needed.
How Much Does a Thyroid Panel with TSH Cost?
| Where You Get Tested | Typical Cost |
|---|---|
| Personalabs | [current price] — physician order included |
| Doctor’s office + lab | $200–$400+ |
| Hospital outpatient lab | $250–$500+ |
HSA and FSA eligible.
Frequently Asked Questions: Thyroid Panel Blood Test
What is included in a thyroid panel?
A comprehensive thyroid panel includes TSH, Free T4, Free T3, and Total T4. TSH measures the pituitary signal that stimulates thyroid hormone production. Free T4 measures the inactive thyroid hormone. Free T3 measures the active hormone that actually enters cells. Together these markers evaluate both thyroid hormone production and conversion — something TSH alone cannot assess.
What is the difference between TSH and Free T3?
TSH is a pituitary hormone that signals the thyroid to produce more hormone — it is an indirect measure of thyroid function. Free T3 is the active thyroid hormone that enters cells and drives metabolic function. Many people have normal TSH but low Free T3 due to impaired T4-to-T3 conversion — this condition is missed by TSH-only testing but detected by a full panel.
Do I need to fast before a thyroid blood test?
No fasting is required for a thyroid panel. You can eat and drink normally before your blood draw. If you take thyroid medication, most guidelines recommend drawing blood before your morning dose to get a true baseline reading rather than a post-dose level.
Can I order a thyroid panel without a doctor?
Yes. Personalabs provides the physician-approved lab order with your purchase. Order the full thyroid panel online, visit any Labcorp location, and get results in 24 to 48 hours. No referral required. HSA and FSA eligible.
Where Can I Get a Thyroid Panel Near Me?
Personalabs partners with Labcorp, giving you access to more than 4,000 lab locations nationwide. Use our lab locator to find a collection site near you. Results are delivered securely to your Personalabs account within 24–48 hours.
