Selenium, RBC
A longer-term read on selenium status, the trace mineral behind antioxidant defense and thyroid function.
Consider this test if:
- Taking selenium supplements and checking whether your level sits in range rather than too high
- Thyroid concerns where selenium status is part of the workup
- Following a restrictive diet or living in a region with low-selenium soil
- Wanting a sustained, multi-month picture of selenium status rather than a recent-intake snapshot
- Investigating hair loss, brittle nails, or GI symptoms that can follow excess intake
- HSA/FSA eligible
- Results delivered to your dashboard · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. If you take selenium or a multivitamin containing it, note the dose and timing, since supplementation raises the result. The sample must be drawn into a trace-element-free (royal blue-top) tube to avoid contamination, so collection follows a specific protocol.
Video consult with your Care Team
A 1:1 call to discuss your health.
What members say on Trustpilot
What this test is for
Selenium is an essential trace mineral the body uses to build glutathione peroxidase (a key antioxidant enzyme) and to convert thyroid hormone from T4 to active T3. Measured in red blood cells, it reflects selenium status over the roughly 120-day lifespan of those cells, so it captures longer-term intake rather than a single recent meal or dose. Low selenium is linked to impaired thyroid hormone conversion, weakened immune response, and, in severe deficiency, cardiomyopathy; high levels usually come from over-supplementation and can cause hair loss, brittle nails, GI upset, and neuropathy. This RBC measurement is the right choice when you want to assess sustained status: the separate serum or plasma selenium test reflects recent intake, and whole-blood selenium is another general-exposure measure.
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 Fast, dashboard-delivered results
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
-
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.
-
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.
-
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.
Mito Membership
$9 /mo
cancel anytime
Without membership
$0
pay as you go
At-cost pricing on labs, scans, and more
Priority turnaround on your results
On-demand clinician consults when you need guidance
Personalized action plans across supplements, exercise, nutrition, and sleep
AI health coaching to help you act on your results
Year-round medical support, with in-chat clinician escalation
All your health records in one personal vault, with trends and biological age tracking
Early access to new diagnostics and product releases
More tests to consider
Loading essentials…
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.
Recently viewed
Loading essentials…