Order Selenium Blood Test from JustLabs for $44. Price includes lab processing at Quest Diagnostics. A one-time $18 collection fee applies per order. No insurance required.
Selenium is an essential trace mineral critical for thyroid hormone metabolism, antioxidant enzyme function, immune defense, and protection against oxidative stress.
Selenium is an essential trace mineral that serves as a cofactor for critical enzymes throughout your body. It's particularly important for thyroid function—selenium-dependent enzymes convert the inactive thyroid hormone T4 into active T3, and protect the thyroid gland from oxidative damage during hormone production.
Beyond thyroid health, selenium is central to your body's antioxidant defense system. It's a key component of glutathione peroxidase, one of the most important antioxidant enzymes that protects cells from free radical damage. Selenium also supports immune function, DNA synthesis, and reproductive health.
Selenium status varies significantly by geographic location because soil selenium content determines how much enters the food chain. Brazil nuts are exceptionally high in selenium, and other good sources include seafood, organ meats, and muscle meats. Both deficiency and excess can cause health problems, making testing valuable for optimizing intake.
Price
$44
Results
3-5 business days
Lab Network
Quest
Fasting
Not Required
What's Measured
What This Test Measures
This test measures the concentration of selenium in your blood serum. Normal levels typically range from 70-150 ng/mL. Optimal levels for thyroid and antioxidant function are often considered to be 100-130 ng/mL.
Who Should Consider This Test
People with thyroid disorders (especially Hashimoto's or Graves' disease), those with autoimmune conditions, individuals with fertility concerns, people living in low-selenium regions, those with malabsorption disorders, anyone with high oxidative stress or chronic inflammation, and people supplementing selenium (to monitor levels).
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
No fasting required. Avoid selenium supplements for 24-48 hours before testing for accurate baseline results. Recent consumption of Brazil nuts can temporarily elevate levels.
Understanding Your Results
Normal serum selenium is typically 70-150 ng/mL. Low levels may impair thyroid function and antioxidant defenses. Optimal levels for thyroid patients are often 100-130 ng/mL. Levels above 200 ng/mL may indicate excess, and toxicity symptoms can occur above 400 ng/mL.
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 3-5 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.
Frequently Asked Questions
$44
Typical hospital cash price: $100–$200
+ $28 in standard lab & physician fees at checkout (no additional bills later)
$18 lab collection + $10 physician order
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