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.
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.
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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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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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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 — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
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