Cortisol vs DHEA: Understanding Two Key Hormone Tests
Cortisol and DHEA are steroid hormones produced in the adrenal glands, and both are frequently measured when a clinician is evaluating the body's stress-hormone system. Although they are sometimes discussed as if they move in lockstep, they are distinct molecules with different functions, different testing methods, and different patterns of change over the lifespan. This guide explains what each hormone does, how laboratory testing for each is performed, and how to read results without overinterpreting a single number.
Key takeaways
- Cortisol and DHEA are different steroid hormones made in the adrenal glands, so a result for one does not substitute for a result for the other.
- Cortisol testing is used mainly to investigate suspected adrenal insufficiency or cortisol excess, while DHEA and its sulfate (DHEA-S) are most often used to evaluate androgen excess or adrenal androgen production.
- Reference ranges for both hormones vary by laboratory, assay method, age, and time of day, so results should always be interpreted against the reporting lab's own range.
- A single abnormal value is rarely diagnostic on its own; clinicians typically combine symptoms, timing of collection, and sometimes repeat or confirmatory testing.
- DHEA-S is often preferred over DHEA for testing because it is more stable in the bloodstream and shows less hour-to-hour fluctuation.
- Neither hormone should be supplemented or suppressed based on a self-ordered test without clinical guidance, because both have meaningful physiologic effects.
What Cortisol and DHEA Actually Are
Cortisol is a glucocorticoid hormone released by the adrenal cortex, the outer layer of the adrenal glands. It follows a daily rhythm, typically peaking in the early morning and reaching its lowest point overnight, and it influences glucose metabolism, blood pressure regulation, immune function, and the body's response to physical stress. Because of that rhythm, the timing of a cortisol measurement matters as much as the number itself.
DHEA, or dehydroepiandrosterone, is an adrenal androgen precursor that the body converts into androgens and estrogens in peripheral tissues. Its sulfated form, DHEA-S, circulates at much higher concentrations and is far more stable than unconjugated DHEA. DHEA-S peaks in early adulthood and then declines gradually with age, which is why age-specific reference ranges are used rather than a single universal cutoff.
How Each Hormone Is Tested
Cortisol can be measured in serum, saliva, or urine, and the choice of specimen depends on the clinical question. A morning serum cortisol is commonly used as an initial screen for adrenal insufficiency, while late-night salivary cortisol or a 24-hour urinary free cortisol collection may be used when cortisol excess is suspected. Because cortisol is pulsatile and follows a diurnal curve, a random value drawn at an unspecified time is difficult to interpret.
DHEA-S is usually measured in serum and requires no special timing because of its stability. Total DHEA can also be measured, but it fluctuates more and is less commonly ordered. In many laboratories, DHEA-S is the preferred marker when evaluating adrenal androgen output, and it may be ordered alongside testosterone, androstenedione, or 17-hydroxyprogesterone depending on the clinical picture.
Why the Two Are Often Considered Together
Cortisol and DHEA are both adrenal steroid products, so conditions that affect the adrenal cortex can alter both. In primary adrenal insufficiency, for example, production of cortisol falls and adrenal androgen output often falls as well. In congenital adrenal hyperplasia, by contrast, cortisol synthesis is impaired while androgen precursors such as DHEA-S may rise, producing a pattern of low cortisol with elevated androgens.
Clinicians sometimes look at the relationship between the two rather than either value alone, but there is no single universally accepted ratio that diagnoses a specific condition. A ratio calculated from one laboratory's assay is not interchangeable with a ratio from another, because assay platforms differ in calibration and cross-reactivity. Any ratio should therefore be interpreted by the ordering clinician in the context of symptoms and other test results.
Interpreting Results Without Overreading Them
Reference intervals for cortisol and DHEA-S are method-dependent and population-dependent. Age, sex, pregnancy status, time of collection, and medications such as corticosteroids or oral contraceptives can all shift results. This is why a value flagged as high or low by one laboratory may fall within range at another, and why comparing a result to a range printed on a different lab report is not meaningful.
Results are also most useful when paired with a clear clinical question. A low morning cortisol in a person with fatigue, weight loss, and low blood pressure suggests a different workup than an isolated low value in someone who feels well. Confirmatory testing, repeat measurement, or dynamic testing such as an ACTH stimulation test may be needed, and decisions about treatment should rest with a qualified clinician rather than a single laboratory report.
What DHEA Supplementation Does and Does Not Do
DHEA is sold as a dietary supplement in some countries, which means it is not held to the same premarket standards as prescription drugs. Its conversion to androgens and estrogens means it can have hormonal effects, and it may interact with conditions or medications sensitive to those hormones. Anyone considering it should discuss the decision with a clinician rather than relying on a test result alone.
There is no reliable evidence that taking DHEA corrects a low cortisol level, because DHEA is not cortisol and does not substitute for it. Conversely, a low DHEA-S does not by itself establish a diagnosis or mandate treatment. The appropriate response to an abnormal result is a conversation with a clinician about the full clinical picture.
Frequently Asked Questions
Is DHEA the same thing as cortisol?
No. Cortisol and DHEA are separate steroid hormones produced in the adrenal cortex. They have different functions, different daily patterns, and different laboratory tests. A result for one does not tell you the value of the other.
Why would a doctor order both cortisol and DHEA-S?
Because both are adrenal products, measuring them together can help characterize conditions that affect the adrenal cortex, such as adrenal insufficiency or disorders of androgen production. The combination can reveal patterns that a single test would miss, but it is interpreted alongside symptoms and other findings.
Does a low DHEA-S mean my cortisol is low?
Not necessarily. The two hormones can change together in some adrenal conditions, but they can also diverge. A low DHEA-S alone does not establish that cortisol is low, and cortisol status is assessed with cortisol-specific testing such as a morning serum cortisol or a stimulation test.
Can I interpret my hormone results without a doctor?
Laboratory values are best interpreted by a clinician who knows your symptoms, medications, and history, and who can compare your result to the reporting laboratory's own reference range. Self-interpretation can lead to unnecessary worry or to missing a condition that needs attention.
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