What is a normal TSH level?

Normal TSH typically ranges from 0.4-4.0 mIU/L. However, optimal TSH for most people feeling their best is often 0.5-2.5 mIU/L. Ranges can vary slightly by lab.

Should I stop taking my thyroid medication before the test?

No, don't stop your medication. However, for the most accurate results, get your blood drawn before taking your daily dose or at least 4 hours after.

Can stress affect TSH levels?

Yes, severe stress can temporarily affect TSH. Chronic stress may suppress TSH slightly. For the most accurate baseline, test when you're not under acute stress.

How often should I test my TSH?

For healthy adults, annual screening is often recommended. If you have thyroid disease or are on medication, your doctor may recommend testing every 6-12 weeks initially, then every 6-12 months once stable.

🦋 ThyroidPopular

TSH Blood Test (Thyroid Stimulating Hormone)

Name: TSH Blood Test (Thyroid Stimulating Hormone)
Brand: Justlabs
SKU: 0000899
Price: 9 USD
Availability: InStock

TSH

The TSH test is the gold standard for evaluating thyroid function. It's the first test doctors order when thyroid problems are suspected.

Thyroid Stimulating Hormone (TSH) is produced by your pituitary gland and tells your thyroid how much hormone to make. When your thyroid is underactive (hypothyroidism), TSH levels rise as your body tries to stimulate more thyroid hormone production. When overactive (hyperthyroidism), TSH drops because less stimulation is needed.

This simple blood test is the most sensitive way to detect thyroid problems, often catching issues before symptoms appear or become severe.

Price

Results

1-2 days

Lab Network

Quest

Fasting

Not Required

What's Measured

TSH

What This Test Measures

This test measures the level of Thyroid Stimulating Hormone (TSH) in your blood. TSH is produced by the pituitary gland in your brain and acts as the "master controller" of your thyroid. Normal TSH levels typically range from 0.4 to 4.0 mIU/L, though optimal ranges may be narrower (0.5-2.5 mIU/L for many people).

Who Should Consider This Test

Anyone experiencing symptoms of thyroid dysfunction such as unexplained weight changes, fatigue, sensitivity to cold or heat, hair loss, or mood changes. Also recommended for those with a family history of thyroid disease, women planning pregnancy, and adults over 35 as part of routine screening.

Health Insights

Conditions Screened

HypothyroidismHyperthyroidismHashimoto's diseaseGraves' diseaseThyroid nodulesPituitary disorders

Related Symptoms

FatigueUnexplained weight gainWeight lossCold intoleranceHeat intoleranceHair lossDry skinBrain fogDepressionAnxietyIrregular periods

When to Get Tested

TSH can be tested any time of day without fasting. For monitoring thyroid medication, test at the same time each day for consistency. Many doctors recommend annual screening for adults, especially women over 35.

Understanding Your Results

High TSH typically indicates an underactive thyroid (hypothyroidism) - your pituitary is working harder to stimulate the thyroid. Low TSH suggests an overactive thyroid (hyperthyroidism) - the pituitary is reducing stimulation because enough hormone is being produced. Your results will include reference ranges and clear indicators if values are abnormal.

What to Expect

After placing your order, you'll receive an email from Rupa Health (our lab order partner) within 24 business hours to sign a consent form and schedule your blood draw at a Quest Diagnostics location.

The blood draw typically takes just a few minutes. Results are usually available within 1-2 business days and will appear in your secure Justlabs dashboard.

Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.