Thyroid-Stimulating Hormone (TSH)
The most sensitive first-line marker for an under- or overactive thyroid.
Consider this test if:
- Fatigue, weight change, cold or heat intolerance, hair thinning, or mood changes with no clear cause
- On levothyroxine or other thyroid medication and checking whether the dose is right
- Pregnant or planning pregnancy, especially with a family or personal history of thyroid or autoimmune disease
- Setting a baseline or rechecking a known borderline (subclinical) result every 6 to 12 months
- Following up after thyroid surgery, radioiodine, or a previously abnormal newborn screen
- HSA/FSA eligible
- Typical results in 1-2 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. Biotin supplements can distort immunoassay results, so stop high-dose biotin for about 48 hours before the draw. TSH varies through the day and is typically highest in the early morning, so for tracking over time, draw at a consistent time. Note any thyroid medication and recent dose changes, since TSH lags weeks behind a dose adjustment.
Video consult with your Care Team
A 1:1 call to discuss your health.
What members say on Trustpilot
What this test is for
Thyroid-stimulating hormone (TSH) is released by the pituitary to tell the thyroid how much thyroid hormone to make, so it is the single most sensitive marker of thyroid function. A high TSH points to an underactive thyroid (hypothyroidism), commonly behind fatigue, weight gain, cold intolerance, constipation, dry skin, hair loss, and low mood; a low TSH points to an overactive thyroid (hyperthyroidism), linked to palpitations, weight loss, anxiety, tremor, and heat intolerance. It is also the standard way to confirm whether thyroid hormone replacement is correctly dosed, with most people on therapy targeted to a TSH around 0.3 to 3.0. One caveat: when clear hypothyroid symptoms exist but TSH is not elevated, a pituitary or hypothalamic cause should be considered, so an abnormal or borderline result is usually followed by free T4.
This is the standalone TSH test, the right starting point for screening and for tracking a known thyroid condition. If you want the next step built in, the TSH with reflex to Free T4 adds T4 automatically when TSH is abnormal; the T4/TSH and full thyroid panels add hormone levels up front, and the TPO or thyroid antibodies tests look for autoimmune causes such as Hashimoto's or Graves'.
- Specimen
- Serum or plasma
- Method
- High-sensitivity assay
- Measures
- Concentration
What you'll learn
-
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.
-
Your personalized action plan. Nutrition, supplements, and training in one clinician-reviewed protocol, updated as your results change.
-
Track your trends. Upload results from any lab and see each biomarker trend over time, so you know what is working.
-
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 1-2 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
-
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
Supplements at 30% off retail prices Coming soon
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. 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.
Recently viewed
Loading essentials…