?DHEA and DHEA-S are closely related hormones, but they are not the same laboratory test.
That distinction matters because DHEA-S is much more abundant and stable in the bloodstream, while DHEA itself changes more over short periods.
As a result, DHEA-S is commonly used when the clinical question concerns adrenal androgen production. Direct DHEA measurement is a separate, more specialist assay and may be requested for a different endocrine reason.
If you are comparing results or deciding which test to order, always check the exact analyte on the request: DHEA or DHEA-S.
DHEA vs DHEA-S at a glance
Feature | DHEA | DHEA-S |
Full name | Dehydroepiandrosterone | Dehydroepiandrosterone sulphate |
Form | Non-sulphated steroid hormone | Sulphated form of DHEA |
Main source | Predominantly adrenal glands, with smaller gonadal contribution | Predominantly adrenal glands |
Blood concentration | Lower | Much higher |
Short-term variation | Greater | Lower / more stable |
Diurnal variation | More noticeable | Less pronounced |
Common clinical role | Specialist direct DHEA assessment | Adrenal androgen assessment |
Fasting | Usually not required | Usually not required |
What is the difference between DHEA and DHEA-S?
DHEA is an adrenal steroid hormone and a precursor used in the synthesis of androgens and oestrogens. DHEA-S is created when a sulphate group is added to DHEA.
That chemical modification changes how the hormone behaves in the circulation. DHEA-S is more stable, circulates at much higher concentrations and shows less short-term variation. The two tests are related, but they are not numerically interchangeable.
Can DHEA and DHEA-S results be compared directly?
No. They are different analytes with different concentrations, units and reference intervals. A DHEA result should be interpreted using the DHEA reference range supplied by the laboratory. A DHEA-S result should be interpreted using the DHEA-S reference range.
Age and sex also matter because adrenal androgen concentrations change across life.
Why is DHEA-S commonly measured?
DHEA-S is frequently used when clinicians want information about adrenal androgen production because it is relatively abundant and stable. It may contribute to assessment of androgen excess, hirsutism or acne, rapid virilisation, selected adrenal disorders, PCOS assessment in appropriate circumstances, and unexpected abnormalities in other androgen measurements.
A DHEA-S result does not diagnose any of these conditions by itself.
What does a direct DHEA blood test tell you?
Direct DHEA measurement assesses the non-sulphated hormone. Because DHEA is less stable and shows greater short-term and diurnal variation, it is generally a more specialist endocrine measurement than DHEA-S.
London Blood Tests offers a separate DHEA Blood Test where direct DHEA has specifically been requested.
What is a DHEA-S blood test?
A DHEA-S test measures dehydroepiandrosterone sulphate in the blood. It is commonly used as an adrenal androgen marker because most circulating DHEA-related hormone is present in the sulphated form.
London Blood Tests provides a separate DHEA Sulphate Blood Test.
DHEA-S and androgen excess in women
DHEA-S can be useful where there are symptoms of androgen excess such as hirsutism, persistent acne, scalp hair thinning in an androgenic pattern, irregular menstrual cycles or virilisation.
A substantially raised DHEA-S result may draw attention towards an adrenal contribution to androgen excess. However, the overall assessment may also include testosterone, SHBG, androstenedione and other hormone tests depending on the presentation.
Is DHEA-S a test for PCOS?
It can contribute to PCOS assessment, but it does not diagnose PCOS.
Current international PCOS guidance prioritises total and/or free testosterone when assessing biochemical hyperandrogenism. If these are not elevated, androstenedione and DHEA-S may be considered, although they are less specific.
PCOS remains a clinical diagnosis requiring the wider reproductive and hormonal picture.
What does high DHEA-S mean?
Higher DHEA-S can occur with increased adrenal androgen production. Possible contexts include PCOS in some women, congenital adrenal hyperplasia, selected adrenal tumours, other causes of adrenal androgen excess and DHEA supplementation.
The degree of elevation matters. Rapidly developing virilisation or markedly abnormal androgen results deserve medical assessment because significant adrenal or ovarian causes may need to be excluded.
What does low DHEA-S mean?
DHEA-S naturally declines with age. Lower concentrations can also occur in some people with adrenal dysfunction, chronic illness or other physiological circumstances.
However, a low DHEA-S result does not diagnose adrenal insufficiency. Where genuine adrenal insufficiency is suspected, cortisol, ACTH and, where appropriate, dynamic endocrine testing are more directly relevant.
Does DHEA-S test for “adrenal fatigue”?
No. “Adrenal fatigue” is not a recognised endocrine diagnosis, and there is no validated DHEA-S test that diagnoses it.
The Endocrine Society states that there is no scientific proof that adrenal fatigue is a true medical condition and no validated test for it.
Persistent fatigue is real, but it has many possible causes. A low DHEA or DHEA-S result should not be used to label someone with adrenal fatigue.
Can supplements alter DHEA or DHEA-S results?
Yes. Taking DHEA supplements can raise DHEA and DHEA-S concentrations and materially affect interpretation.
Tell the clinician or laboratory about DHEA supplementation, hormonal therapy and relevant steroid medicines before testing. Do not stop prescribed treatment simply to change a laboratory result without medical advice.
Does DHEA-S need to be tested in the morning?
DHEA-S is relatively stable across the day, so strict morning collection is usually less important than it is for direct DHEA or cortisol. DHEA itself has greater short-term and diurnal variation, so consistent timing can be useful when serial direct DHEA measurements are being compared.
Which test should you choose?
Clinical question | More relevant test or approach |
Clinician specifically requested direct DHEA | DHEA |
Assessing adrenal androgen production | Often DHEA-S |
Suspected PCOS | Broader androgen/reproductive hormone assessment |
Suspected adrenal insufficiency | Cortisol/ACTH-led assessment rather than DHEA-S alone |
Taking DHEA supplements | Exact analyte requested by the reviewing clinician |
Rapid virilisation | Broader urgent endocrine assessment rather than one isolated test |
Neither test is inherently “better”. The right choice depends on the clinical question.
DHEA and DHEA-S Testing at London Blood Tests
Test | Current price | Typical turnaround | Sample | Usual role |
£185 | 7–10 business days | Venous blood | Specialist direct DHEA measurement | |
£88 | Approximately 10 business days | Venous blood | Adrenal androgen assessment |
Fasting is not usually required for either test when measured on its own.
Booking DHEA Testing in London
Private DHEA and DHEA-S testing is available through London Blood Tests at participating clinics and through eligible home collection. Before booking, check the exact wording on the clinical request. DHEA and DHEA-S are related but separate assays.
Our Private Blood Tests in London guide explains collection and appointment options.
Frequently Asked Questions
What is the difference between DHEA and DHEA-S?
DHEA is the non-sulphated hormone and shows more short-term variation. DHEA-S is the sulphated, more abundant and more stable circulating form.
Can I compare a DHEA result directly with DHEA-S?
No. They are different tests with different concentrations, units and reference ranges.
Which is more commonly used for adrenal androgen assessment?
DHEA-S is commonly used because it is more stable and predominantly reflects adrenal androgen production.
What does high DHEA-S mean?
It can occur with increased adrenal androgen production, PCOS in some women, congenital adrenal hyperplasia, selected adrenal tumours or DHEA supplementation. The result does not identify the cause on its own.
What does low DHEA-S mean?
It may reflect age or several physiological and medical factors. It does not by itself diagnose adrenal insufficiency.
Does DHEA-S diagnose adrenal fatigue?
No. Adrenal fatigue is not a recognised endocrine diagnosis and DHEA-S is not a validated test for it.
Can DHEA supplements affect the test?
Yes. Supplementation can increase measured DHEA and DHEA-S and should be disclosed before interpretation.
The Bottom Line
DHEA and DHEA-S come from the same adrenal androgen pathway, but they are separate laboratory biomarkers.
DHEA is the non-sulphated form and varies more over short periods. DHEA-S is more abundant and stable, which is why it is commonly used when assessing adrenal androgen production.
Neither test should be used as a standalone diagnosis of PCOS, adrenal insufficiency or so-called adrenal fatigue.
The right test depends on the clinical question, and results should be interpreted using the correct age-, sex- and assay-specific reference interval.
London Blood Tests offers both DHEA and DHEA-S testing as separate assays.