Lab Tests

Cortisol

Morning cortisol tells you how your body’s stress system is functioning — whether it’s running normally, stuck on overdrive, or running on empty.

Optimal: 10–20 mcg/dL (morning) Elevated: >25 mcg/dL Low: <5 mcg/dL 4 min read

Cortisol is your body’s primary stress hormone. It should peak in the morning (waking you up, giving you energy) and drop to its lowest at night (letting you sleep). When this pattern breaks — from chronic stress, poor sleep, or overwork — everything from muscle to mood to metabolism suffers.

Optimal range
10–20 mcg/dL (7–9 AM)
Why it matters
Stress, sleep, muscle, metabolism
How often to test
As needed (symptoms)
Fasting required?
Yes — morning, 7–9 AM
Dive deeper into the research

What is the cortisol test?

Cortisol is made by your adrenal glands in response to stress signals from your brain. It follows a precise daily rhythm: it peaks about 30 minutes after you wake up (the "cortisol awakening response"), then drops steadily all day, hitting its lowest point around midnight.

A morning blood draw captures your peak. If it’s too high, your stress system is overworked. If it’s too low, it may be exhausted or there could be an adrenal problem. For a full picture of your daily rhythm, a 4-point salivary cortisol test is more informative.

What your number means

Morning CortisolWhat it meansWhat to do
<5 mcg/dLVery low — see a doctorRule out adrenal insufficiency. Don’t self-treat.
5–10 mcg/dLBluntedSleep quality is likely poor. Try ashwagandha, rhodiola, stress management.
10–20 mcg/dLOptimalYour stress axis is working well. Maintain sleep and stress habits.
20–25 mcg/dLBorderline highYou’re running hot. Ashwagandha KSM-66, better sleep, stress reduction.
>25 mcg/dLElevated — investigateRepeat test. Physician evaluation if persistent.

How to improve it

The #1 intervention

Sleep is the single most powerful cortisol regulator. 7.5–9 hours, consistent timing, dark room, cool temperature. Everything else is secondary.

For supplement support: Ashwagandha KSM-66 (300–600mg/day) has the best evidence — 27–30% cortisol reduction in clinical trials. Magnesium glycinate and L-theanine help as well.

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Frequently Asked Questions

What is a normal morning cortisol level?

Lab normal is 6–23 mcg/dL. Optimal is 10–20 mcg/dL. Below 5 needs medical evaluation. Above 25 chronically warrants investigation. Always test at 7–9 AM, fasting.

Which supplements lower cortisol?

Ashwagandha KSM-66 (300–600mg/day) has the strongest evidence — 27–30% cortisol reduction in multiple RCTs. Phosphatidylserine, rhodiola rosea, and magnesium glycinate also have supporting evidence. Sleep remains the most powerful tool.

Can I test cortisol at home?

Yes — salivary cortisol kits let you test 4 times during the day (waking, noon, evening, bedtime), showing your full daily rhythm. This is more useful than a single morning blood draw for understanding your stress axis.

Does exercise raise or lower cortisol?

Both. Exercise acutely spikes cortisol, but regular moderate training improves your cortisol regulation over time. Overtraining without adequate recovery, however, keeps cortisol chronically elevated — so balance intensity with rest.

Research & Science

What chronic high cortisol does

Chronically elevated cortisol breaks down muscle protein, promotes visceral fat storage, raises blood sugar, suppresses testosterone and DHEA, disrupts sleep, and weakens your immune system. It’s one of the main mechanisms by which chronic stress accelerates aging.

The cortisol:DHEA-S ratio

The ratio of cortisol to DHEA-S tells you about your HPA axis balance. High cortisol with low DHEA-S means your stress system is dominating your anabolic/recovery system — a pattern very common in overworked Indian professionals.

India-specific context

Long work hours, poor sleep culture, and high psychological pressure make cortisol dysregulation extremely common in urban India. Salivary testing is increasingly available through labs like Thyrocare and specialty wellness clinics.

Connected supplements

Ashwagandha is the primary cortisol-targeting supplement. Phosphatidylserine (400–600mg/day) blunts exercise-induced cortisol spikes. Rhodiola rosea is better for the "burnout" pattern. Magnesium glycinate supports HPA axis regulation.

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