Selenium
An essential trace mineral tied to thyroid function, antioxidant defense, and immune health.
Consider this test if:
- Tracking selenium status while taking a supplement and deciding whether to continue or stop
- On long-term parenteral nutrition or a restricted metabolic diet
- Investigating thyroid symptoms alongside other thyroid markers
- Possible occupational or environmental selenium exposure
- Confirming you are not over-supplementing after stacking multiple mineral products
- HSA/FSA eligible
- Typical results in 2-4 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. If you take a selenium supplement, note the dose and timing, since serum levels respond quickly to recent intake; keeping a consistent routine makes results comparable over time. Collection requires a metal-free tube to avoid contaminating the sample.
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What this test is for
Selenium is a trace mineral your body uses to build antioxidant enzymes and to convert thyroid hormone into its active form. This serum or plasma test measures circulating selenium, which reflects recent intake and is the standard way to check for deficiency or for excess from over-supplementation or occupational exposure. Low levels are linked to impaired thyroid function and weakened antioxidant and immune defenses, while high levels can cause selenosis with hair loss, brittle nails, and digestive upset. It is also monitored in people on long-term parenteral nutrition and in children on restricted metabolic diets.
Serum selenium tracks short-term status and responds quickly to changes in diet or supplements. The separate red-blood-cell selenium test reflects longer-term stores over the lifespan of red cells, and the whole-blood test captures both pools, so choose RBC or whole-blood if you want a longer-term average rather than recent intake.
- Specimen
- Serum or plasma
- Measures
- Mass concentration
What you'll learn
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Insights that connect the dots. A clinician reads your whole picture, not one result in isolation, connecting family history, past results, and lifestyle into clear next steps.
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Your personalized action plan. Nutrition, supplements, and training in one clinician-reviewed protocol, updated as your results change.
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Track your trends. Upload results from any lab and see each biomarker trend over time, so you know what is working.
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Never miss a recheck. Mito tells you what is worth retesting and when, then reminds you so nothing slips.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Typical results in 2-4 days
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
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Without membership
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost, covering the lab and what it takes to run the service. It is never a profit on the test itself. Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9 per month, and any applicable lab order or draw fee is itemized before you pay.
Where do I get tested?
Choose an available partner lab at checkout. If your cart contains multiple blood tests, Mito helps consolidate the eligible tests at one lab when possible. At-home kits and scans follow the collection or appointment process shown on their product page.
Is this eligible for HSA/FSA?
Yes. Eligible tests can be paid for with an HSA or FSA card at checkout.
When will I get my results?
Your results appear in your Mito dashboard after the laboratory completes processing. A clinician then reviews them before your analysis and personalized action plan are finalized. Timing varies by test, and specialty assays and at-home kits may take longer.
Do I need a physician's order?
No. Mito provides the laboratory order when one is required, so you do not need to arrange a separate physician visit before purchasing.
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