A four point cortisol test is a way to measure your cortisol levels at multiple times across one day to see your daily (diurnal) cortisol pattern. It’s most commonly done with saliva samples collected at set times (often morning, midday, afternoon/evening, and bedtime), because salivary cortisol reflects the free (biologically active) cortisol in your body. PMC+1

This type of testing is often used in functional/integrative care to understand whether your cortisol rhythm may be contributing to symptoms like sleep disruption, fatigue, anxiety/irritability, cravings, and midlife “wired-but-tired” patterns.

What Cortisol Is Supposed To Look Like

Cortisol follows a natural circadian rhythm. In a typical pattern:

• Cortisol rises around waking and peaks in the morning (including the “cortisol awakening response”)
• It gradually declines across the day
• It is lowest at night (near midnight) PMC+1

A four point test is designed to show whether your curve looks like that general pattern—or if it appears “flatter,” “shifted,” or higher later in the day.

What Times Are Usually Tested?

Most four point cortisol panels use four saliva collections at specific time windows. Common examples include:

• Shortly after waking (sometimes also a separate 30-min-after-waking sample in certain protocols)
• Around midday
• Late afternoon or early evening
• At bedtime or late night Rupa Health+1

The goal is to see the overall rhythm rather than relying on a single “snapshot.”

What It Can Help Explain

A four point cortisol test may add useful context when someone is experiencing patterns such as:

• Sleep problems (difficulty falling asleep, frequent waking, waking too early)
• Morning fatigue or needing a lot of caffeine to function
• Afternoon crashes
• Anxiety, irritability, or feeling “on edge”
• Cravings (especially late afternoon/evening)
• Midsection weight gain alongside stress and sleep strain

It can also be used to track changes over time when you’re working on stress physiology, sleep, and metabolic resilience.

What It Does Not Diagnose

This is important: a four point cortisol test is not the standard test for diagnosing many endocrine diseases.

For example:

• If the concern is Cushing syndrome (pathologically high cortisol), the Endocrine Society recommends screening with tests such as late-night salivary cortisol, 24-hour urine free cortisol, or a dexamethasone suppression test—not a general “diurnal cortisol wellness curve.” Endocrine Society+1
• If the concern is adrenal insufficiency, clinicians often start with morning serum cortisol and confirm with specific stimulation testing when indicated (not a 4-point saliva profile). (This is standard endocrine practice; your clinician can guide appropriate testing.)

So, the four point test is best viewed as a pattern tool that can support a bigger clinical picture—not a standalone diagnosis.

Why Saliva Is Often Used

Salivary cortisol testing is popular for rhythm testing because it is:

• Noninvasive
• Convenient to collect at home at multiple times
• Reflective of free cortisol, which is the active fraction PMC+1

Late-night salivary cortisol is also an established endocrine tool when Cushing syndrome is being evaluated, which supports the broader idea that saliva can be a valid medium when collected and analyzed correctly. Endocrine Society+1

How To Get The Most Accurate Results

Because cortisol is sensitive to daily inputs, a few practical factors matter:

• Timing matters: follow the collection times exactly
• Avoid contamination: don’t eat, drink (especially caffeinated/alcoholic), smoke/vape, or brush teeth right before collecting (blood from gums can interfere)
• Note your context: poor sleep, night shifts, acute illness, intense training, or major life stress can shift results—sometimes that’s the point, but it needs to be interpreted accordingly PMC+1

If you work night shifts or have a very atypical sleep schedule, cortisol rhythm interpretation can be more complex because circadian rhythms may be shifted. PMC

What Results Usually Mean In Real Life

Most people don’t need to memorize cortisol curves. The practical questions are:

• Does your pattern align with your symptoms (sleep, energy, mood, cravings)?
• Are there obvious rhythm issues that suggest focusing on sleep timing, recovery, blood sugar stability, nervous system regulation, and lifestyle scaffolding?
• Do we need to rule out medical conditions or medication effects that could be influencing cortisol?

In other words: the value is in how the results guide your next steps—not in “optimizing a number.”

Science Section (Selected References)

• Endocrine Society Clinical Practice Guideline: Diagnosis Of Cushing’s Syndrome (Includes Late-Night Salivary Cortisol As A First-Line Screening Test)
• Journal Of The Endocrine Society (2020): Salivary Cortisol And Cortisone (Context, Methods, Clinical Use; Late-Night Salivary Cortisol Performance)
• PMC Review (2011): Cortisol Awakening Response + Diurnal Pattern (Peak After Waking, Lowest At Night)
• Endocrine Society Guideline (2016): Cortisol Secretion Is Pulsatile And Circadian (High In Morning, Nadir Around Midnight)

How Peace And Calm Health Functional Medicine Can Help

At Peace and Calm Health Functional Medicine in Lakewood, CO, I use cortisol rhythm testing as one part of understanding stress physiology and sleep patterns—especially when symptoms include fatigue, “wired but tired” energy, mood changes, stubborn weight gain, and sleep disruption.

If a four point cortisol test makes sense for your situation, we’ll use it as a tool (not a label), alongside your symptoms, history, gut/metabolic patterns, and lifestyle. Then we translate results into a personalized plan that may include nervous system strategies, sleep optimization, nutrition support, and functional medicine tools based on what your body needs.

To explore next steps, book a Clarity Call here:
https://www.drjenniferhorton.com/work-with-me

You can learn more about wellness programs here:
https://www.drjenniferhorton.com/wellness-programs

Medically reviewed by Dr. Jennifer Horton, DO, ABFM, IFMCP

This content is for educational purposes and does not substitute personalized medical advice.