Cortisol, Free and Total
The active, unbound fraction of your main stress hormone alongside the total, useful when binding proteins distort the standard reading.
Consider this test if:
- Investigating symptoms of cortisol excess such as central weight gain, easy bruising, high blood pressure, or muscle weakness
- Investigating possible adrenal insufficiency with fatigue, low blood pressure, weight loss, or salt craving
- Pregnant, on estrogen, or with low albumin, where total cortisol can mislead and the free fraction is more reliable
- Following up an abnormal screening cortisol with a more precise free and total measurement
- 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
Cortisol follows a daily rhythm, peaking in the early morning and falling through the day, so collection time matters and most baseline draws are done around 8 a.m. Note any corticosteroid use (oral, topical, inhaled, or injected) since these affect results, and tell the lab if you take estrogen or are pregnant. Acute illness, physical stress, and poor sleep can transiently raise cortisol. Fasting is not required.
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What this test is for
Cortisol is the adrenal hormone that regulates blood sugar, blood pressure, metabolism, inflammation, and the body's response to stress. Most cortisol in the blood is bound to carrier proteins; only the free fraction is biologically active, and this test measures both the free and total levels in serum. Free cortisol is particularly useful when binding proteins are altered, as in pregnancy, estrogen therapy, or low albumin, situations where total cortisol alone can read misleadingly high or low. Elevated levels point toward Cushing's syndrome, while consistently low levels raise the question of adrenal insufficiency (Addison's disease), which can present with fatigue, weakness, low blood pressure, weight loss, and salt craving.
This serum panel reports both fractions at a single point in time. If your question is the daily rhythm specifically, the timed AM and PM serum tests or salivary cortisol address that, and 24-hour urinary free cortisol is the standard measure of total daily output for a Cushing's workup.
Biomarkers tested
Includes 2 biomarkers
Cortisol is the hormone your adrenal glands release to manage stress, blood sugar, blood pressure, and your wake-sleep rhythm, peaking in the morning and tapering through the day. High levels can point to chronic stress, Cushing's syndrome, or overtraining, while low levels suggest adrenal insufficiency (Addison's disease) or a pituitary problem, either of which can drive fatigue, weight changes, poor sleep, low blood pressure, and brain fog. Testing it establishes a baseline for how your body handles stress and helps investigate unexplained exhaustion, mood swings, or a sleep-wake cycle that feels out of sync, especially when paired with ACTH or DHEA-S for fuller context.
- Specimen
- Serum or plasma
- Measures
- Mass concentration
- 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 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
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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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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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