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Cortisol Test

Cortisol Test

January 21, 2026
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Do I need a Cortisol test?

Feeling constantly stressed, exhausted despite sleeping, or struggling with stubborn weight gain? Could your cortisol levels be playing a role?

Cortisol is your body's primary stress hormone. When it's out of balance, it can leave you feeling drained, anxious, or unable to manage weight effectively.

Testing your cortisol gives you a valuable snapshot of how your body handles stress, helping pinpoint whether hormonal imbalances are fueling your exhaustion or weight struggles. It's the essential first step to personalizing your lifestyle and health plan so you can reclaim your energy.

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With Superpower, you have access to a comprehensive range of biomarker tests
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Get tested with Superpower

If you’ve been postponing blood testing for years or feel frustrated by doctor appointments and limited lab panels, you are not alone. Standard healthcare is often reactive, focusing on testing only after symptoms appear or leaving patients in the dark.

Superpower flips that approach. We give you full insight into your body with over 100 biomarkers, personalized action plans, long-term tracking, and answers to your questions, so you can stay ahead of any health issues.

With physician-reviewed results, CLIA-certified labs, and the option for at-home blood draws, Superpower is designed for people who want clarity, convenience, and real accountability - all in one place.

Key benefits of Cortisol testing

  • Reveals how well your adrenal glands respond to stress and regulate energy.
  • Spots adrenal dysfunction early, including Cushing's syndrome or Addison's disease.
  • Explains fatigue, weight changes, mood swings, or unexplained high blood pressure.
  • Guides treatment for suspected hormone imbalances affecting metabolism and immunity.
  • Tracks recovery when managing chronic stress or adrenal-related conditions.
  • Protects bone health by flagging prolonged high cortisol that weakens bones.
  • Best interpreted with ACTH levels and your symptom pattern for accurate diagnosis.

What is Cortisol?

Cortisol is a steroid hormone produced by the adrenal glands, two small organs that sit atop your kidneys. It's made in the outer layer of these glands (the adrenal cortex) and released into your bloodstream in a rhythmic pattern throughout the day. Cortisol belongs to a class of hormones called glucocorticoids, which regulate metabolism and immune function.

Your body's built-in stress responder

Cortisol is often called the "stress hormone" because it surges when you face physical or emotional challenges. But it does far more than manage stress. It helps control blood sugar levels, regulates blood pressure, reduces inflammation, and influences how your body uses fats, proteins, and carbohydrates for energy.

The rhythm that keeps you running

Cortisol follows a natural daily cycle, peaking in the early morning to help you wake up and gradually declining through the day. This rhythm supports your energy, alertness, and metabolic balance. Measuring cortisol reveals how well your adrenal glands are functioning and whether your body's stress response system is in balance.

Why is Cortisol important?

Cortisol is your body's primary stress hormone, produced by the adrenal glands and essential for managing energy, inflammation, blood pressure, and how you respond to physical or emotional demands. It follows a natural daily rhythm, peaking in the morning to help you wake and declining through the day. Healthy cortisol levels typically sit in the mid-range, with values that are context-dependent - morning levels are naturally higher than evening.

When cortisol runs too low

Insufficient cortisol, seen in adrenal insufficiency, leaves the body unable to mount a stress response or maintain blood pressure and blood sugar. Fatigue becomes profound, salt cravings emerge, and dizziness or fainting can occur with standing. Women may experience menstrual irregularities, while children may show poor growth and recurrent low blood sugar.

When cortisol climbs too high

Chronic elevation, whether from prolonged stress or a tumor producing excess hormone, drives weight gain around the abdomen and face, weakens bones, thins skin, and raises blood sugar and blood pressure. Mood shifts toward anxiety or depression. Women may develop irregular periods and excess facial hair, while men can experience reduced libido and muscle loss.

The long view on stress and resilience

Cortisol connects your brain, metabolism, immune system, and cardiovascular health. Persistent imbalance increases risk for diabetes, osteoporosis, infections, and heart disease. Understanding your cortisol pattern offers insight into how well your body adapts to life's demands.

What do my Cortisol results mean?

Low cortisol values

Low values usually reflect reduced adrenal output or impaired signaling along the hypothalamic-pituitary-adrenal axis. This can occur with primary adrenal insufficiency, where the glands themselves are damaged, or secondary insufficiency due to pituitary dysfunction. Chronic suppression from long-term steroid use is another common cause. Low cortisol may manifest as fatigue, low blood pressure, poor stress tolerance, and difficulty maintaining blood sugar during fasting or illness.

Optimal cortisol values

Being in range suggests your adrenal glands are responding appropriately to the body's demands at the time of testing. Cortisol follows a strong circadian rhythm, peaking in the early morning and declining through the day. Optimal morning values typically sit in the mid to upper portion of the reference range, reflecting healthy stress responsiveness and metabolic regulation.

High cortisol values

High values usually reflect increased adrenal activity, whether from physiological stress, illness, or a pathologic process like Cushing syndrome. Elevated cortisol can result from pituitary tumors, adrenal tumors, or ectopic hormone production. Chronic elevation may contribute to central weight gain, high blood sugar, elevated blood pressure, immune suppression, and bone loss.

Factors that influence cortisol interpretation

Cortisol interpretation depends heavily on timing of the blood draw, recent stress or illness, and medications including oral contraceptives and corticosteroids. Pregnancy raises cortisol naturally. Single random values are less informative than timed samples or dynamic testing.

Method: FDA-cleared clinical laboratory assay performed in CLIA-certified, CAP-accredited laboratories. Used to aid clinician-directed evaluation and monitoring. Not a stand-alone diagnosis.

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Similar biomarker tests from Superpower

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Frequently Asked Questions

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How it works
What should I expect during a blood draw?
  • A trained phlebotomist will guide you through the process.
  • A tourniquet is placed on your arm, the site is cleaned, and a small needle is used to collect blood into one or more tubes.
  • Results are usually ready in about a week.
  • Most people feel only a quick pinch.
  • The needle is removed, gentle pressure is applied, and a bandage is placed.
How do I prepare for a blood draw?
  • Drink plenty of water beforehand — hydration makes veins easier to find.
  • Wear loose sleeves so your arm is easy to access.
  • Follow any fasting instructions you’ve been given.
  • Let us know if you’re on medications, have fainted before, or have needle anxiety.
What should I do after my blood draw?
  • Press gently on the site for a few minutes.
  • Keep the bandage on for 4-6 hours.
  • Skip heavy lifting or strenuous exercise for the rest of the day.
  • Drink extra water to rehydrate.
  • Monitor the site for redness, swelling, or pain.
How do I book a blood draw with Superpower?

Your membership includes:

  • An annual full body test and report across 100+ biomarkers
  • A personalized action plan to optimize your biomarkers and reach your health goals
  • A dashboard to centralize your health data and track changes across a lifetime
  • Access to a health concierge for questions on your plan and help scheduling
  • Plus a marketplace of curated health products and services cheaper than amazon

Many concierge clinics charge $10k – $100k for their services, we’ve built technology to make the world’s best healthcare as accessible as possible via an all-in-one membership.

Where can I take my blood test?

Superpower is currently available in the following US states:

  • Alabama
  • Arizona
  • California
  • Colorado
  • Connecticut
  • Delaware
  • District of Columbia
  • Florida
  • Georgia
  • Idaho
  • Illinois
  • Indiana
  • Kansas
  • Maine
  • Maryland
  • Massachusetts
  • Michigan
  • Minnesota
  • Missouri
  • Montana
  • Nebraska
  • Nevada
  • New Hampshire
  • New Jersey
  • New Mexico
  • New York
  • North Carolina
  • Ohio
  • Oklahoma
  • Oregon
  • Pennsylvania
  • South Carolina
  • Tennessee
  • Texas
  • Utah
  • Vermont
  • Virginia
  • Washington
  • West Virginia
  • Wisconsin
Our testing
Does Superpower replace my primary care provider?

Superpower specializes in prevention-based testing and treatments and is not intended for emergency or immediate health issues.

While you will have a Superpower care team, your annual membership is designed to complement a primary care doctor if you have one, not replace them.

We are happy to help you share any test results with an outside provider to ensure you receive well-rounded medical care.

How fast are blood test results and how do I read them?

Your annual lab test panel takes about a week to process. We will text you as soon as they become available in your dashboard. Other types of tests may have different testing windows. The Superpower concierge is your own health assistant who helps answer your questions on your results, ensure smooth scheduling, coordination of any office-based tests, specialist referrals as needed, and navigating you to interface with your care team.

Does Superpower accept health insurance?

Superpower membership and products are all eligible for HSA/FSA funding.

We see Superpower like a gym membership for those committed to prevention and performance. Superpower is a bridge between wellness and healthcare. Health insurance traditionally focuses on reactive care whereas, at Superpower, we believe it’s never too early to start looking out for your long-term health.

What if I want more than 1 blood test per year?

Absolutely — you're not limited to just one. Your membership includes one comprehensive 100+ biomarker blood test each year, but if you'd like to track your progress more closely, you can add extra tests at any time. Each additional full-panel test costs $179. You can order as many as you'd like throughout the year.

“Best health check of my entire life.”

Vinay Hiremath, Founder of Loom

“Life changing”

Jordi Hayes, Founder of Capital.xyz

Frequently Asked Questions about Cortisol Test

What is cortisol and what does the “stress hormone” actually do in the body?

Cortisol is a steroid hormone made by the adrenal glands (located on top of your kidneys). As a glucocorticoid, it helps regulate metabolism and immune function by raising blood sugar, breaking down proteins, and releasing fatty acids for energy. It also modulates inflammation, supports blood pressure control, and influences your sleep-wake cycle. Although called the “stress hormone,” cortisol is essential for everyday survival and resilience.

How does cortisol follow a circadian rhythm, and why does timing matter for cortisol testing?

Cortisol follows a daily (circadian) pattern: it typically peaks in the morning to help you wake up and gradually declines at night to support rest. Because levels change throughout the day, the timing of your sample strongly affects your results. A single cortisol measurement can be misleading if timing is ignored. For accurate interpretation, results should be considered alongside symptom timing and often paired with ACTH levels.

What are the key benefits of cortisol testing for adrenal function and stress-related symptoms?

Cortisol testing measures your body’s main stress hormone to assess adrenal function and your stress-response capacity. It can help explain symptoms such as fatigue, weight changes, mood swings, or unexplained blood pressure shifts. Testing may spot adrenal disorders like Cushing’s syndrome or Addison’s disease earlier, guide treatment for suspected hormone imbalances affecting energy and metabolism, and track response to steroid medications or adrenal-targeted therapies over time.

What do low cortisol results mean, and what symptoms can adrenal insufficiency cause?

Low cortisol usually suggests reduced adrenal output or insufficient pituitary signaling (low ACTH). It may occur in primary adrenal insufficiency (Addison disease), secondary adrenal insufficiency, or after long-term steroid use suppresses natural production. Low cortisol can impair your ability to maintain blood pressure and blood sugar and respond to stress. Common symptoms include profound fatigue, weakness, weight loss, low blood pressure, dizziness on standing, and salt cravings.

What do high cortisol levels mean, and when could it indicate Cushing’s syndrome?

High cortisol can reflect chronic stress, overproduction by the adrenal glands, excess ACTH stimulation, severe illness, or Cushing syndrome (including certain tumors). Persistently elevated cortisol may contribute to central weight gain (trunk/face), insulin resistance, high blood pressure, bone loss, thinner skin, and immune suppression. Mood changes such as anxiety, depression, insomnia, and brain fog can also occur, especially when cortisol stays elevated over time.

What does it mean if my cortisol is “optimal,” and why do labs define normal ranges broadly?

An “in-range” cortisol result generally suggests healthy adrenal function and an appropriate stress response. Typically, morning cortisol is higher shortly after waking and then declines through the day, supporting stable energy, immune balance, and cardiovascular tone. However, labs often define broad reference ranges, and “normal” depends heavily on sample timing, recent stress, sleep, and acute illness. Results are best interpreted with clinical context, symptoms, and timing.

What factors can affect cortisol test results, including medications, pregnancy, stress, and sleep?

Cortisol varies significantly with time of day, stress level, sleep quality, and acute illness. Pregnancy naturally raises cortisol. Medications can also shift results - steroid medications may suppress or alter cortisol patterns, and oral contraceptives can influence measured levels. Because many factors change cortisol from day to day, a single test may not capture your typical pattern. Interpretation should account for symptoms, timing, and relevant medical history.

How can cortisol testing help distinguish stress-related fatigue from thyroid issues or true adrenal dysfunction?

Because cortisol influences energy, metabolism, blood pressure, and mood, abnormal levels can mimic or overlap with other conditions. Cortisol testing can clarify whether symptoms like fatigue, weight changes, and mood swings are more consistent with chronic stress patterns, thyroid-related issues, or adrenal dysfunction. For better diagnostic accuracy, cortisol results are often best interpreted alongside ACTH levels and the timing of symptoms relative to your daily cortisol rhythm.

Why is ACTH often measured with cortisol, and how does it improve diagnosis?

ACTH (adrenocorticotropic hormone) is the pituitary signal that tells the adrenal glands to produce cortisol. Measuring ACTH with cortisol helps determine whether abnormal cortisol is driven by the adrenal glands themselves (primary adrenal issues) or by altered pituitary signaling (secondary causes). This combined view improves diagnostic accuracy when evaluating adrenal insufficiency, suspected Cushing syndrome, or cortisol abnormalities related to long-term steroid use, especially when symptoms and test timing are considered.

Can long-term steroid medications affect cortisol levels, and how is cortisol used to track therapy response?

Yes. Long-term steroid use can suppress the body’s natural cortisol production and alter adrenal function, potentially leading to low cortisol results and reduced stress tolerance. Cortisol testing can help monitor how the adrenal system is responding over time, especially when adjusting steroid medications or adrenal-targeted therapies. Tracking cortisol patterns may support safer treatment decisions and help explain symptoms such as fatigue, low blood pressure, or unstable blood sugar during therapy changes.

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