Also Known As
Thyroid-Stimulating Hormone, TSH, Thyrotropin, Thyrotropic Hormone
What Is a TSH Blood Test?
A TSH (Thyroid-Stimulating Hormone) blood test measures the level of TSH produced by your pituitary gland. TSH controls how much thyroid hormone your thyroid produces — so when TSH levels are off, it’s usually a sign your thyroid is either working too hard or not hard enough.
The TSH test is the first-line screening tool for thyroid disorders and one of the most commonly ordered hormone tests in routine health care. A single blood draw is all it takes to get a clear picture of your thyroid function.
What Does the TSH Blood Test Measure?
The TSH test measures the concentration of thyroid-stimulating hormone in your blood. TSH is produced by the pituitary gland and acts as the control signal to your thyroid — telling it to produce more or less thyroid hormone (T3 and T4).
When your thyroid is underactive (hypothyroidism), your pituitary pumps out more TSH trying to stimulate it — so TSH goes high. When your thyroid is overactive (hyperthyroidism), TSH drops low because the pituitary senses too much thyroid hormone already in circulation.
TSH Normal Range: 0.5 – 5.0 mIU/L
| TSH Level | What It May Indicate |
|---|---|
| Below 0.5 mIU/L | Hyperthyroidism (overactive thyroid) |
| 0.5 – 5.0 mIU/L | Normal thyroid function |
| Above 5.0 mIU/L | Hypothyroidism (underactive thyroid) |
Reference ranges may vary slightly by laboratory. Always review results with a qualified healthcare provider.
Who Should Get a TSH Blood Test?
Consider ordering a TSH test if you experience symptoms of an underactive or overactive thyroid, want to establish a baseline, or are monitoring a known thyroid condition.
Symptoms of hypothyroidism (high TSH) include:
- Unexplained fatigue or sluggishness
- Unexplained weight gain
- Cold intolerance
- Hair thinning or loss
- Depression or brain fog
- Constipation
- Dry skin
Symptoms of hyperthyroidism (low TSH) include:
- Unexplained weight loss
- Rapid or irregular heartbeat
- Anxiety or irritability
- Excessive sweating
- Tremors
- Difficulty sleeping
Also recommended for:
- Women over 35 (thyroid disorders are significantly more common in women)
- Anyone with a family history of thyroid disease
- People being evaluated for fertility issues — thyroid dysfunction is a common contributing factor
- Anyone starting or monitoring GLP-1 weight loss medications — thyroid function is commonly evaluated before and during treatment
- People on thyroid medication who want to monitor their levels between doctor visits
TSH Blood Test Preparation
No fasting is required. You can eat and drink normally before your TSH test.
One important exception: If you are currently taking thyroid medication (such as levothyroxine/Synthroid), get your blood drawn before taking your morning dose that day. Taking thyroid medication before the draw can temporarily suppress TSH and give a falsely low reading.
No other special preparation is needed.
How Much Does a TSH Blood Test Cost?
A TSH blood test at Personalabs costs $78 — physician lab order included. No insurance required.
| Where You Get Tested | Typical Cost | Notes |
|---|---|---|
| Personalabs | $78 | Physician order included |
| Doctor’s office visit + lab | $150–$350+ | Copay + separate lab bill |
| Hospital outpatient lab | $200–$500+ | Facility fees apply |
| Endocrinologist visit + lab | $250–$600+ | Specialist visit + lab fees |
HSA and FSA eligible. Pay with pre-tax healthcare dollars — your TSH test qualifies as a reimbursable medical expense.
Where Can I Get a TSH Blood Test Near Me?
After ordering online, visit any of our 4,000+ partner patient service centers nationwide — including Quest Diagnostics and Labcorp locations in all 50 states.
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 About the TSH Blood Test
Can I order a TSH blood test without a doctor?
Yes — in most states. Personalabs provides a physician-approved lab order as part of your purchase, so you don’t need your own doctor’s referral. Our network physician approves your order within 2–4 hours. A small number of states restrict direct-to-consumer lab testing; contact us to confirm availability in your state.
Do I need to fast before a TSH blood test?
No fasting is required for a TSH test. You can eat and drink normally. The one exception: if you take thyroid medication, draw your blood before your morning dose for the most accurate result.
How much does a TSH blood test cost at Personalabs?
A TSH blood test at Personalabs costs $78, with the physician lab order included. No insurance is required and there are no hidden fees. Your TSH test is HSA and FSA eligible.
What is a normal TSH level?
The standard normal range is 0.5 to 5.0 mIU/L for adults, though some labs and providers use slightly different ranges. TSH above 5.0 typically suggests hypothyroidism; TSH below 0.5 typically suggests hyperthyroidism. Your results will include the reference range used by the specific lab that processed your sample.
What is the difference between TSH and T3/T4 thyroid tests?
TSH is the screening test — it’s the first thing checked because it’s the most sensitive indicator that something is off with thyroid function. T3 and T4 are the actual thyroid hormones, and they’re usually tested as a follow-up when TSH is abnormal to pinpoint the specific issue. If your TSH comes back outside the normal range, adding a Free T4 or Free T3 test gives a more complete picture.
How long does it take to get TSH blood test results?
Results are typically available in your Personalabs account within 24–48 hours of your blood draw. You’ll receive a notification when they’re ready.
Can thyroid medication affect my TSH result?
Yes — significantly. Taking levothyroxine (Synthroid, Tirosint) or other thyroid medications before your blood draw can suppress TSH and make your result appear lower than your true baseline. Always draw blood before your morning dose on test day.
Is TSH testing recommended before starting weight loss medications?
Yes. Many providers screen thyroid function before starting GLP-1 medications like Ozempic, Wegovy, or Mounjaro because hypothyroidism can independently cause weight gain and fatigue that may be mistaken for other conditions — and because thyroid function affects metabolic response to treatment. A TSH test is a fast, affordable way to rule out thyroid issues as a contributing factor.
