Selenium is an essential mineral your body needs in small amounts to stay healthy. Selenium helps your thyroid work properly, supports your immune system, and protects your cells from damage. The Selenium Test measures your body’s selenium level in the blood. By understanding your selenium level, you can take steps to maintain optimal health and address any imbalances that might affect wellbeing. This test may be helpful if you are curious about your nutritional status, experiencing symptoms of deficiency, or had potential exposure to selenium.
Preparation: No special preparation is needed.
The selenium test measures the level of selenium in your blood. Selenium is an essential mineral that plays a role in thyroid function, immune health, and antioxidant processes. Selenium deficiency symptoms may include fatigue, hair loss, or mental fog, while excessive levels can be toxic. This test helps ensure your selenium levels are within a healthy range.
Selenium is an essential mineral for overall health and is found in foods like seafood, meat, eggs, and grains. If your diet is limited, you might not be getting enough. People who follow a vegetarian or vegan diet may have lower selenium intake than others. Testing helps ensure you're maintaining optimal selenium levels, which is crucial for proper thyroid function, immune system support, and antioxidant protection.
Selenium deficiency can lead to various health issues, including weakened immune function and thyroid problems. If you're experiencing symptoms like fatigue, hair loss, or weakened immune system, this selenium deficiency test may help identify if abnormal levels might be contributing to your symptoms.
Selenium supports both immune and thyroid function—two important pillars of overall health. Checking your selenium levels is one piece of the puzzle in understanding your overall health, to ensure your body has what it needs to stay balanced, energized, and resilient.
1. Selenium in diet. MedlinePlus. Updated October 11, 2021. Accessed August 19, 2025. https://medlineplus.gov/ency/article/002414.htm
2. Selenium – Health Professional Fact Sheet. National Institutes of Health. Updated March 26, 2021. Accessed August 19, 2025. https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/
<p>1. Selenium in diet. MedlinePlus. Updated October 11, 2021. Accessed August 19, 2025. <a href="https://medlineplus.gov/ency/article/002414.htm" target="_blank" title="Article1" rel="noopener noreferrer">https://medlineplus.gov/ency/article/002414.htm</a></p> <p>2. Selenium – Health Professional Fact Sheet. National Institutes of Health. Updated March 26, 2021. Accessed August 19, 2025. <a href="https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/" target="_blank" title="Selenium-HealthProfessional" rel="noopener noreferrer">https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/</a><b></b></p>
Simply purchase this test online. A healthcare provider will review and approve your test requests; no healthcare provider visit is required.
Visit a Labcorp location near you for sample collection. Visits may be scheduled online.
View your easy-to-read results online in your Labcorp Patient™ account, including Linked Accounts. For certain results that require prompt attention, you will also be contacted by phone or mail.
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Symptoms of selenium deficiency may include:
However, these symptoms can be related to other health conditions, which is why a selenium blood test is the most reliable way to determine status.
Optimal selenium serum levels can vary depending on factors like age, sex, and overall health status. Consult with your healthcare provider if you have questions or concerns about the results of your selenium level blood test.
Several factors can lead to elevated selenium levels in your blood:
Your testing will be performed in a CLIA-certified clinical laboratory. Labcorp provides leading-edge medical laboratory tests and services through a national network of primary clinical laboratories and specialty testing laboratories. Our labs perform regular quality assurance testing to ensure our results are accurate.
Your results will be provided to you through our secure online portal to view or print. Results are also made available through a secure portal to the independent healthcare provider who placed your test order. If you are accessing your results through your Labcorp Patient™ account, all users linked to the account will have access to all OnDemand test results. Results may also be provided to a local, state, and/or federal health authority; for example, many states require the testing laboratory and physician to report test results for certain communicable diseases, such as COVID-19, to local or state health departments.
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Visit the Labcorp OnDemand® website to browse and purchase laboratory tests and create your Labcorp Patient™ account to view your results. All Labcorp OnDemand testing requires an order from an authorized healthcare professional. For your convenience, Labcorp OnDemand has contracted with independent professional entities (collectively, Providers) to deliver healthcare provider services. Visit a Labcorp location for sample collection; or, if using an at-home collection kit, collect your sample yourself. We’ll let you know when your results are ready and can be accessed through your Labcorp Patient™ account.
