Reading the cortisol curve on your DUTCH Test

Cortisol's daily rhythm

Cortisol is a hormone made by the adrenal glands. It helps regulate blood sugar, blood pressure, inflammation and your response to stress. It follows a daily pattern: MedlinePlus notes that cortisol is normally highest in the morning and much lower by late afternoon, falling further toward bedtime.

Many things push that pattern around. Stress, exercise, illness, temperature extremes, alcohol, poor sleep and some medicines can raise cortisol, and long-term or recently stopped steroid medicines are the most common cause of abnormal levels.

What the DUTCH Test adds

Standard testing for adrenal disease uses blood, 24-hour urine or late-night saliva. The DUTCH Test takes a different approach: you collect several small urine samples on filter paper at set times, such as on waking, in the morning, afternoon and evening. This shows the shape of your daily curve without multiple lab visits.

The report usually shows free cortisol at each time point and an estimate of total cortisol output from its metabolites. Your clinician looks at both: how much cortisol you are making and how it is distributed through the day.

Common patterns and what may sit behind them

• A typical curve: a clear morning peak tapering through the day
• High evening values: often linked to late stress, screens, late exercise, alcohol or poor sleep
• A flat or low morning: may reflect disrupted sleep, shift work, depression, chronic illness or the timing of sample collection
• High overall output: can reflect ongoing stress, obesity, alcohol or, rarely, a medical condition needing further tests
• Low overall output: may relate to steroid medicines, recent illness or, rarely, adrenal insufficiency

Free cortisol versus metabolites

DUTCH reports often show two related numbers. Free cortisol is the small fraction excreted unchanged and reflects what was active at each collection time. Metabolized cortisol, estimated from breakdown products, gives a sense of how much your adrenal glands produced over the day.

The two do not always move together. Thyroid function, body weight, liver processing and some medicines can change how quickly cortisol is broken down. A low free cortisol with normal metabolites, for example, can mean cortisol is being cleared faster rather than produced in lower amounts. This is one reason a DUTCH cortisol result should be interpreted by a clinician who can consider your thyroid labs, weight and medication list rather than read from a color-coded chart alone.

Why we do not diagnose 'adrenal fatigue'

You will often see a flat cortisol curve labeled 'adrenal fatigue' online. The Endocrine Society states that no scientific proof supports adrenal fatigue as a true medical condition and that no test can detect it. Its concern is that the label can cause real problems, such as sleep apnea, depression or true adrenal insufficiency, to be missed.

The society also warns that adrenal hormone supplements taken when they are not needed can suppress your own adrenal glands for months. We do not prescribe them based on a cortisol curve.

When cortisol needs standard testing

The DUTCH Test is not used to diagnose Cushing's syndrome or adrenal insufficiency. If your symptoms or results suggest either, your clinician will recommend validated tests and, usually, an in-person endocrinology evaluation.

Signs that call for that route include unexplained weight gain with purple stretch marks, easy bruising and muscle weakness, or, at the other end, weight loss, dizziness on standing, salt craving and darkening skin. Seek urgent care for severe vomiting, confusion or fainting.

Collecting samples that can be trusted

A cortisol curve is only as good as its timing. Collect on a fairly typical day, not after a red-eye flight or a night of drinking. Follow the kit's timing precisely and write down the actual times. Tell your clinician about steroid creams, inhalers, joint injections and oral steroids, which can change results. MedlinePlus advises not stopping any medicine without talking to your provider first.

Turning the curve into a plan

Most action steps from a cortisol pattern are about sleep and daily rhythm: a consistent wake time, morning light, earlier exercise, limiting alcohol and caffeine late in the day, and addressing night sweats, pain or possible sleep apnea. Your clinician reads the curve alongside your symptoms and blood work, not in isolation.

The DUTCH Test costs $449 one-time with no membership fee, and your price is confirmed at the eligibility review. It is a laboratory developed test that has not been reviewed by the FDA, and reference ranges are less established than for standard blood tests.