DHEA-S: adrenal synthesis, intracrinology, adrenopause and immunity

Dehydroepiandrosterone sulfate (DHEA-S, also DHEAS) is a major circulating adrenal C19 steroid. Its relatively abundant, persistent pool supplies tissues that can import steroid sulfates and convert them into other steroids. Understanding this reservoir requires distinguishing adrenal production, sulfation, transport, local desulfation and conversion into androgen or estrogen receptor ligands. DHEA and DHEA-S also have experimental actions that do not fit a simple precursor-only model.

Concentrations usually fall during adult aging. That observation has inspired the term adrenopause and hypotheses linking adrenal androgen decline to immune, metabolic and neurological aging. However, an age association, a cellular mechanism and a benefit from supplementation are three different propositions. Clinical trials support some specific effects in selected populations; they do not establish DHEA as a general intervention against aging, infection, dementia, sarcopenia or premature death.

The adrenal compartment and its development

The adult adrenal cortex contains an outer zona glomerulosa, a larger zona fasciculata and an inner zona reticularis next to the medulla. The glomerulosa predominantly produces mineralocorticoids under renin–angiotensin and potassium regulation; the fasciculata produces cortisol, principally under ACTH regulation. The reticularis has a characteristic enzyme profile favoring DHEA and its sulfate. Approximate zone proportions describe particular specimens and methods, rather than fixed percentages in every gland. Reticularis cells commonly contain relatively little lipid, abundant steroidogenic organelles and age-related lipofuscin, but appearance alone does not quantify steroid output (Miller and Auchus, 2011; Rege and Rainey, 2012).

Human fetal adrenal physiology differs markedly from adult physiology. A prominent fetal zone supplies DHEA-S that participates, together with the fetal liver and placenta, in fetoplacental estrogen synthesis. The fetal zone involutes after birth. Later, adrenarche involves development of adrenal androgen secretion, often becoming evident around six to eight years of age. It is distinct from gonadarche: activation of the hypothalamic–pituitary–gonadal axis is a different process. DHEA-S generally reaches its highest adult concentrations in early adulthood and subsequently declines, with substantial variation by sex and individual (Rainey et al., 2004; Rege and Rainey, 2012).

Human adrenal C19 production should not be inferred directly from a standard rodent experiment. Adult mouse and rat adrenals ordinarily lack the substantial CYP17A1-dependent androgen output seen in humans. Species differences include enzyme expression, circulating steroid concentrations and exposure after an administered dose. This does not mean that only humans can synthesize DHEA, or that every mammal has the same adrenal pathway.

Cholesterol to DHEA: compartments, electrons and competing routes

Adrenal cholesterol comes from lipoprotein uptake, intracellular stores and de novo synthesis. LDL receptor-mediated uptake, SR-BI-mediated cholesterol delivery and the HMG-CoA reductase pathway contribute in different proportions according to physiological conditions. StAR facilitates acute delivery of cholesterol to the inner mitochondrial membrane. It is a cholesterol-transfer regulator, not the enzyme that cleaves the side chain.

At that membrane, CYP11A1 converts cholesterol into pregnenolone through sequential hydroxylation and side-chain cleavage. Hydroxylation at C22 and C20 precedes cleavage of the C20–C22 bond, changing a C27 substrate into a C21 steroid. The electrons originate from NADPH and reach CYP11A1 through ferredoxin reductase and ferredoxin, commonly designated FDXR and FDX1. This mitochondrial electron-transfer system differs from the POR system used by microsomal CYP17A1 (Miller and Auchus, 2011).

Pregnenolone enters reactions associated with the endoplasmic reticulum. Human CYP17A1 catalyzes both 17α-hydroxylation and 17,20-lyase activity. Its Δ5 route can be summarized as:

$$\text{Pregnenolone}\xrightarrow{\mathrm{CYP17A1}}17\alpha\text{-hydroxypregnenolone}\xrightarrow{\mathrm{CYP17A1}}\mathrm{DHEA}.$$

Both reactions require appropriate reducing equivalents, supplied by NADPH–cytochrome P450 oxidoreductase, POR. CYP17A1 does not perform hydroxylation independently of an electron donor. Cytochrome b5 preferentially enhances the lyase reaction. The combination of CYP17A1, POR and b5, together with relatively low HSD3B2 activity, helps explain why reticularis cells favor DHEA production.

HSD3B2 can convert Δ5 steroids into Δ4 steroids, including pregnenolone to progesterone and DHEA to androstenedione. Human CYP17A1 has different efficiencies with Δ5 and Δ4 substrates; the hydroxypregnenolone route is particularly important for DHEA synthesis. Low reticularis HSD3B2 expression is not complete absence, and the adrenal steroid metabolome contains more than a single linear route. This distinction also matters when discussing alternative and 11-oxygenated androgen pathways (Rege and Rainey, 2012).

Auchus, Lee and Miller (1998) showed that b5 could enhance lyase activity without acting as a direct electron-transfer donor in their reconstituted system, supporting an allosteric explanation. The magnitude of stimulation depends on the substrate and experimental configuration. Later work on substrate-specific interactions means that a categorical claim that b5 can never participate in electron-transfer effects is too broad. Likewise, phosphorylation can modulate CYP17A1 interactions and activity experimentally, but individual kinase assignments and fold changes should not be presented as a universal quantitative explanation of human aging. (Liu et al., 2021).

SULT2A1, activated sulfate and the DHEA-S reservoir

DHEA carries a 3β-hydroxyl group. Cytosolic SULT2A1 transfers an activated sulfo group to this hydroxyl, producing DHEA-S. SULT2A1 belongs to the cytosolic sulfotransferase family and can form a dimer; a monomer has a molecular mass of roughly 34–35 kDa. Its gene lies on chromosome 19. These properties are different from those of the membrane-associated steroid sulfatase that reverses steroid sulfation.

The sulfo donor is PAPS, 3′-phosphoadenosine 5′-phosphosulfate. The following are biochemical pathway summaries; protonation states are omitted:

$$\mathrm{DHEA}+\mathrm{PAPS}\xrightarrow{\mathrm{SULT2A1}}\mathrm{DHEAS}+\mathrm{PAP}.$$ $$\begin{aligned} \mathrm{SO_4^{2-}}+\mathrm{ATP}&\longrightarrow\mathrm{APS}+\mathrm{PP_i},\\ \mathrm{APS}+\mathrm{ATP}&\longrightarrow\mathrm{PAPS}+\mathrm{ADP}. \end{aligned}$$

APS denotes adenosine 5′-phosphosulfate, PAP denotes 3′-phosphoadenosine 5′-phosphate, and PPi denotes inorganic pyrophosphate. Bifunctional PAPS synthases perform sulfate activation and APS phosphorylation. PAPSS2 is particularly relevant to adrenal androgen sulfation. This pathway consumes ATP; it is not a coenzyme A-dependent reaction, and vitamin B5 is not established as a specific means of restoring adrenal PAPS production.

Structural interpretation requires identifying the correct enzyme. Human SULT2A1 contains the catalytic histidine His99; assigning His108 from a different sulfotransferase misidentifies the residue. Structures such as 1EFH, containing PAP, and 1J99, containing DHEA, illustrate ligand-dependent organization of the binding region. Protein flexibility and substrate positioning contribute to catalytic specificity. PDB 4GRA represents SULT1A1, not SULT2A1, and cannot establish SULT2A1 pocket residues or its steroid-binding mechanism. Estrogen sulfotransferase SULT1E1 is also a distinct enzyme, even though all use activated sulfate. (Cook et al., 2010).

Sulfation adds mass and polarity. DHEA has a molecular mass of about 288.42 g/mol; the free-acid form of DHEA-S is about 368.49 g/mol. The circulating sulfate ester is predominantly an anion. Molecular masses of the isolated anion and pharmaceutical salts differ, so a laboratory conversion must use the chemical convention associated with its result.

Sulfation can reduce immediate access to conventional androgen and estrogen receptor activation while creating a transportable precursor reservoir. It is not simply irreversible disposal. Conversely, calling DHEA-S entirely inert overlooks experimental neuroactive effects. A genetic example shows why a low DHEA-S concentration cannot automatically mean a lack of androgen action: PAPSS2 deficiency can impair sulfation and redirect DHEA toward active androgen production. Human family studies demonstrate altered steroid metabolism and androgen excess despite low DHEA-S; phenotype and circulating androgens vary (Oostdijk et al., 2015).

Steroid sulfatase and local access to the precursor

Steroid sulfatase, STS, hydrolyzes steroid sulfate esters, including DHEA-S and estrone sulfate. Its X-linked gene lies in the Xp22 region; STS deficiency causes X-linked ichthyosis and changes steroid sulfate metabolism. STS is associated with the endoplasmic reticulum, with a catalytic domain positioned toward the lumen and a membrane-associated region. The placental enzyme structure 1P49 provides evidence for this organization (Hernandez-Guzman et al., 2003).

Its unusual catalytic residue is formylglycine, generated from a precursor cysteine by the formylglycine-generating enzyme encoded by SUMF1. The hydrated formylglycine participates in sulfate ester cleavage. This chemistry should not be confused with a cytochrome P450 oxidation or with SULT2A1 using PAPS in reverse. A simplified net reaction is:

$$\mathrm{DHEAS}+\mathrm{H_2O}\xrightarrow{\mathrm{STS}}\mathrm{DHEA}+\text{inorganic sulfate}.$$

The exact ionic balance depends on protonation convention. Tissue expression, substrate import and intracellular enzyme access determine how much circulating DHEA-S can be used locally. Widespread STS expression does not mean that every tissue has identical activity or that every cell possesses a complete androgen and estrogen synthesis pathway.

Circulating concentrations, binding and clearance

DHEA-S concentrations are normally much higher, on a molar basis, than DHEA concentrations, and its circulating turnover is slower. DHEA-S is substantially associated with albumin and does not share testosterone's pattern of high-affinity SHBG binding. Binding fractions depend on assay conditions and physiological context; an exact universal percentage or a claim that albumin binding can never change is unwarranted.

For example, 1–10 ng/mL DHEA corresponds to approximately 3.47–34.7 nmol/L, whereas 1–4.5 µg/mL DHEA-S corresponds to approximately 2.71–12.21 µmol/L using the free-acid mass. These are conversion examples, not reference intervals for all ages and sexes. Comparing DHEA-S with testosterone yields different fold ratios in men and women and at different ages; there is no universal “300–500 times” relationship.

The distinction between endogenous clearance and an oral concentration curve matters. Oral DHEA undergoes substantial conversion to DHEA-S and other metabolites, making the measured time course longer and more complex than clearance of an isolated circulating DHEA tracer. Literature half-life estimates should therefore be accompanied by the administered form, route and measurement method (Kroboth et al., 1999; Arlt et al., 1998).

Organic anion transporters participate in steroid sulfate movement. OATP family members and OAT4 can be involved in specific tissues, but localization and direction matter. Apical renal reuptake alone is not a complete return-to-blood pathway; basolateral transport and renal handling also contribute. Biliary export, deconjugation and microbial metabolism can affect steroid metabolites, without establishing a single dominant enterohepatic circuit for every person. DHEA hydroxylation involves several enzymes; 7α-hydroxylation is associated particularly with CYP7B1 and should not be assigned wholesale to CYP3A4. Kidney, liver, inflammatory illness and medications can alter measured concentrations. Relative stability does not make DHEA-S independent of these influences (Mueller et al., 2015).

Intracrinology: tissue steroid production and inactivation

Intracrinology describes production and action of active steroids within the tissue receiving a precursor. It differs conceptually from secretion of an active hormone by a distant endocrine gland. DHEA-S may enter a cell through an anion transporter, undergo STS-mediated desulfation, and provide DHEA for a tissue-specific enzyme network (Labrie et al., 2001).

One route uses HSD3B activity to form androstenedione, followed by reductive 17β-hydroxysteroid dehydrogenase activity to form testosterone. AKR1C3 is important in several peripheral tissues; HSD17B3 is especially associated with testicular steroidogenesis and should not be assumed to perform the same role in every tissue. Another route reduces DHEA to androstenediol before HSD3B-dependent formation of testosterone. SRD5A1 or SRD5A2 can convert testosterone into dihydrotestosterone, DHT. Aromatase, CYP19A1, converts appropriate androgens into estrogens; estrone–estradiol interconversion depends on reductive and oxidative 17β-HSD enzymes. HSD17B1 favors estradiol formation in relevant tissues, whereas HSD17B2 can promote oxidation of active 17β-hydroxysteroids.

Androgen receptor and estrogen receptor signaling consequently depends on more than the precursor concentration. Transport, STS, local enzyme expression, competing pathways, receptor abundance and steroid inactivation all matter. Postmenopausal peripheral estrogen production becomes particularly important, but DHEA-S is not the sole possible precursor: DHEA, androstenedione and residual ovarian androgen production also contribute. In men, testicular secretion remains a major source of circulating testosterone; a fixed claim that adrenal DHEA supplies half of every man's active androgens would obscure this physiology.

Local action is followed by metabolism and conjugation to varying degrees. AKR1C-mediated reduction and other transformations can precede glucuronidation involving UGT2B enzymes, including UGT2B7, UGT2B15 and UGT2B17. Androsterone glucuronide and 3α-androstanediol glucuronide reflect aspects of peripheral androgen metabolism, but they are not specific readouts of DHEA-S conversion. Hormone products can leave tissues, and administered DHEA can raise circulating testosterone and estradiol. Intracrinology therefore does not guarantee that supplementation has no systemic hormonal consequences.

Bone, muscle, adipose tissue and skin illustrate the diversity of this network. Bone cells respond to androgen and estrogen signaling that can influence osteoblast function and the OPG–RANKL balance controlling osteoclast development. Muscle androgen signaling intersects with protein synthesis, but precursor availability alone does not determine muscle gain. Adipose stromal cells can express aromatase and contribute to peripheral estrogen production; that should not be generalized to identical activity in all adipocytes. Skin steroid conversion influences sebaceous activity, hair follicles and other local functions, explaining why increased precursor exposure may produce acne or hirsutism as well as changes in skin hydration. Hormone-dependent tumors can also exploit steroid precursors and local enzyme activity. Local conversion is therefore relevant to both physiological function and disease (Labrie et al., 2001; Mueller et al., 2015).

Adrenopause, cortisol and the limits of biomarker interpretation

Adrenopause denotes the gradual age-associated reduction in adrenal androgen production. It is not the abrupt ovarian transition of menopause, nor a diagnosis that explains every symptom of aging. A longitudinal study of 614 adults observed an average DHEA-S decline of approximately 2% per year over five years, while DHEA declined faster. Population averages do not specify an individual's future slope or prove that restoring an earlier concentration restores an earlier biological age (Nafziger et al., 1998).

Changes in reticularis structure, steroidogenic enzyme expression, cofactor interactions and regulation are plausible contributors. However, exact claims that aging universally eliminates a particular percentage of reticularis cells, reduces b5 by a fixed multiple or produces adrenal PAPS deficiency require direct human evidence. Experimental progenitor-cell and signaling models, including those developed in rodents, cannot by themselves establish a human reticularis regeneration mechanism. ATP is required for PAPS synthesis, but that fact does not demonstrate that mitochondrial ATP limitation causes adrenopause in a given patient.

Cortisol and DHEA-S trajectories can diverge. ACTH stimulates both relevant adrenal compartments, yet enzyme organization and regulation differ. Cortisol secretion, circadian pattern, binding and feedback can also change with age, illness and stress. It is consequently too simple to describe cortisol as invariably unchanged while DHEA-S alone falls, or to infer that DHEA directly competes with cortisol at the glucocorticoid receptor.

A cortisol:DHEA-S ratio is meaningful only when the units and sampling context are explicit:

$$R=\frac{C_{\mathrm{cortisol}}\;(\mathrm{nmol/L})}{C_{\mathrm{DHEAS}}\;(\mathrm{nmol/L})}.$$

Here both concentrations are molar and the ratio is dimensionless. If DHEA-S is reported in µmol/L, multiply its numerical value by 1000 before using a cortisol result in nmol/L. Hypothetical values of 300/10000 give 0.03; 450/1000 give 0.45, a fifteenfold difference. These examples demonstrate arithmetic, not normal young and old profiles or a therapeutic threshold.

Phillips et al. (2010) studied 4,255 male Vietnam-era veterans with morning samples and subsequent mortality follow-up. Lower DHEA-S and a higher cortisol:DHEA-S ratio were associated with several mortality outcomes. This observational relationship is compatible with confounding, illness-related hormonal changes and multiple causal pathways. It does not show that supplementing DHEA lowers mortality, validate 0.10 as a treatment cutoff, or establish MRI hippocampal damage and telomere loss as outcomes of that study. A serum DHEA-S result is an adrenal steroid measurement, not a validated stand-alone biological-age clock, immune-reserve score or mitochondrial-function test.

Neurosteroid signaling: mechanisms and human evidence

DHEA and DHEA-S are discussed as neuroactive steroids because they can influence neuronal signaling. Production within nervous tissue has been investigated, but the contribution of local human brain steroidogenesis versus peripheral supply remains an important qualification. Lipophilic DHEA and anionic DHEA-S differ in access across biological barriers. A high concentration in an experimental animal brain, or persistence after an endocrine manipulation, cannot establish the same quantitative origin or brain:plasma ratio in humans (Baulieu, 1997; Maninger et al., 2009).

Experimental DHEA-S can negatively modulate GABA-A receptor-mediated currents. Reducing an inhibitory current is a mechanistic effect, not proof that an oral supplement safely improves alertness or memory. Effects involving NMDA signaling and sigma-1 receptors are likewise sensitive to concentration, preparation and indirect interactions. A generic NMDA or sigma-1 protein structure does not identify a DHEA-S binding site or establish high-affinity binding to every proposed subunit. (Majewska et al., 1990).

Sigma-1 is an intracellular chaperone associated with endoplasmic-reticulum and mitochondria contact regions. Interactions with BiP and IP3 receptor signaling can influence calcium handling under experimental conditions. IP3 receptors are calcium channels, not calcium pumps. Downstream changes in mitochondrial function, oxidative-stress responses, CREB–BDNF signaling and cell survival provide hypotheses for neuroprotection; they should not be recast as established prevention of human ischemic injury, Alzheimer's disease or depression by routine DHEA supplementation (Maurice and Su, 2009).

Small clinical depression trials deserve a separate description. Schmidt et al. (2005) studied 46 adults aged 45–65 in a randomized, double-blind crossover trial. Six weeks of DHEA, with a high experimental dose schedule, improved depression ratings relative to placebo. That result concerns a selected symptomatic population and a short trial; it does not validate general cognitive rejuvenation or an unsupervised dosing protocol. In contrast, the DAWN trial in older adults did not demonstrate a general improvement in cognition or quality of life. Population, outcome and duration determine what each study can support. (Kritz-Silverstein et al., 2008).

Endothelium and nitric oxide

DHEA can stimulate endothelial signaling experimentally. Liu and Dillon (2002), in bovine aortic endothelial preparations, described high-affinity membrane binding and Gi2/Gi3-associated activation of endothelial nitric oxide synthase. Their report appeared in the Journal of Biological Chemistry. The characterized binding activity was a putative receptor mechanism; it was not identification of a universally accepted cloned DHEA receptor gene.

Related experimental work connects DHEA exposure with Src, PI3K, Akt and eNOS signaling. Nitric oxide can activate soluble guanylate cyclase, increase cGMP and relax vascular smooth muscle. Specific phosphorylation sites depend on the experimental pathway and protein convention. These mechanisms explain why vascular effects have been investigated, but do not establish prevention of myocardial infarction, thrombosis or cardiovascular mortality. The distinction between endothelial mechanisms and clinical risk assessment also matters when interpreting ApoB and atherogenic particle burden.

Immune homeostasis and immunosenescence

Glucocorticoids and adrenal androgen-related steroids can influence immune cells through different mechanisms. Glucocorticoid receptor signaling regulates inflammatory transcription, lymphocyte survival and tissue responses, with effects determined by dose, duration and context. Experimental DHEA effects on cytokines, apoptosis or glucocorticoid metabolism do not make DHEA a universal competitive antagonist of cortisol, nor demonstrate clinically preserved thymic output.

Cell and animal studies describe changes in NF-κB-related signaling, cytokine production and lymphocyte responses. Such findings require the stimulus, cell type and concentration: a decrease in one preparation does not imply a fixed 40–60% reduction in IL-6, TNF or IL-1 in humans. The human studies in the original literature actually demonstrate this complexity (Hazeldine et al., 2010).

Casson et al. observed increased NK cytotoxicity alongside changes that included reduced CD4 representation and altered mitogen responses. Describing the study solely as improved T-cell immunity would be misleading. Khorram et al. observed increases in stimulated IL-2 and IL-6, rather than universal IL-6 suppression; T-cell counts and subsets did not simply revert to a young pattern. NK-cell number, cytotoxicity assays and cytokine release are distinct outcomes, and none is interchangeable with infection-free survival.

Immunosenescence includes changing naïve and memory compartments, terminal differentiation and variable functional responses. CD45RA alone does not uniquely identify a naïve T cell: terminally differentiated memory cells can re-express it. CD28 loss and CD57 expression characterize some differentiated populations, but senescence, exhaustion and a senescence-associated secretory phenotype are not synonymous labels for every such cell. Current cited evidence does not establish that DHEA restores telomerase, regenerates the thymus, reverses all these phenotypes or improves vaccine protection in older people.

Muscle, glucose metabolism and bone

Potential anabolic signaling has encouraged research into DHEA and sarcopenia. Androgen and IGF-related pathways can activate Akt, influence TSC–Rheb regulation of mTORC1 and affect p70S6 kinase and 4E-BP1-dependent protein synthesis. Myostatin and protein degradation provide additional regulatory inputs. These pathways describe how muscle cells respond to signals; they do not imply that a given oral precursor dose reliably adds a fixed amount of muscle in every older adult.

Villareal and Holloszy (2006) studied DHEA together with resistance training during the final four months of a ten-month trial. Evidence of an interaction with training in that setting should remain distinct from DHEA alone. Nair et al. (2006), in a two-year trial of older adults with low DHEA-S, found no meaningful improvement in strength, aerobic performance, body composition, insulin sensitivity or quality of life attributable to DHEA. Differences in exercise, participants and measurements help explain why individual results cannot be generalized into a universal anabolic protocol.

Experimental metabolic pathways include AMPK activation, TBC1D4-related control of GLUT4 trafficking, hepatic gluconeogenic gene expression and lipid oxidation involving PPARα, CPT1 and peroxisomal enzymes. The phosphorylation-dependent regulation of a Rab GTPase-activating protein is more specific than saying AMPK simply inhibits an enzyme to make glucose disappear. Most such molecular pathways require careful separation of animal and human evidence. The AMPK discussion in berberine research provides context for this mechanism-to-outcome distinction; effects of one compound do not establish effects of another.

Apostolova et al. (2005) showed reduced amplification of glucocorticoid action in experimental adipose systems, involving regulation of 11β-HSD1 expression and related factors such as H6PD and C/EBPα. This is not evidence that DHEA acts as a clinically established direct noncompetitive 11β-HSD1 inhibitor. Villareal and Holloszy's 2004 six-month trial reported reduced abdominal fat and improved an insulin-action measure in a small older population. The later negative two-year study prevents treating these findings as a universal HOMA-IR reduction or a proven diabetes therapy.

Bone effects may reflect local or circulating sex-steroid conversion, changes in osteoblast and osteoclast signaling, and site-specific responses. Runx2, collagen synthesis, osteocalcin and OPG–RANKL are relevant mechanistic concepts, but changes in them do not prove fracture prevention. Jankowski et al. (2006) randomized 140 older adults to 50 mg/day DHEA or placebo for twelve months. Results included a lumbar-spine BMD increase in women and modest, analysis-dependent hip effects. The study was not a two-year trial, did not show universal gains in lean mass, and has DOI 10.1210/jc.2005-2484. The two-year Nair trial also reported small bone changes at selected sites without broad functional improvement.

Supplementation: forms, doses and safety boundaries

Oral micronized DHEA, topical preparations and other delivery methods produce different exposures. Absorption, first-pass sulfation and conversion to active sex steroids vary with formulation and the person. SULT2A1 is relevant to DHEA sulfation; estrogen sulfotransferase SULT1E1 should not be substituted as the principal DHEA enzyme. A plasma peak after one preparation cannot be applied to every product or used to claim that sublingual delivery rescues cognition.

The often-cited 50 mg/day dose comes from particular research protocols, not a universal anti-aging recommendation. Arlt et al. (1998) investigated nine young women with dexamethasone-induced suppression of adrenal androgen production; 100 mg produced supraphysiological exposure in that setting. Their later adrenal-insufficiency crossover trial involved 24 women and four-month treatment periods, with improvements in some well-being and sexuality measures, and decreases in HDL cholesterol. These populations and findings differ from healthy older people (Arlt et al., 1999).

The DHEAge study administered 50 mg/day or placebo for one year to 280 adults aged 60–79. It reported selected changes in bone, skin and libido, particularly in subsets of women, and did not demonstrate harmful steroid accumulation during that year (Baulieu et al., 2000). This was not a meta-analysis, did not prove lifelong cancer safety and did not establish global protection against aging. The two-year Nair findings are especially important when weighing the broader promises.

DHEA can increase androgen and estrogen exposure. Acne, hirsutism, androgen-related hair changes and changes in lipid concentrations are relevant adverse effects. Hormone-dependent disease requires particular clinical attention; intracellular conversion does not protect breast, endometrial or prostate tissue from steroid effects. Absence of a large PSA change in a small short trial cannot establish prostate-cancer safety, and proposed balancing of androgen and estrogen signaling is not proof of cancer prevention.

The 2014 Endocrine Society guideline advises against routine DHEA prescription in women with low androgen concentrations because benefits and long-term risks are insufficiently defined. The 2016 primary adrenal insufficiency guideline suggests a limited trial in selected women with persistent low libido, depressive symptoms or low energy despite optimized glucocorticoid and mineralocorticoid replacement. This is a specific disease context, with reassessment and discontinuation when benefit is absent, rather than a general longevity protocol.

Laboratory interpretation and proposed companion supplements

A laboratory result should be interpreted using its assay-specific, age- and sex-appropriate reference interval, clinical question, medications and disease context. Immunoassays and LC-MS/MS methods can differ. Fatigue, depressed mood, reduced libido, cognitive complaints and loss of muscle are nonspecific; low DHEA-S alone does not diagnose adrenal insufficiency. Cortisol, ACTH and other endocrine investigations are selected according to clinical findings rather than automatically ordered as a universal anti-aging panel.

Unit conversion is essential:

$$C_{\mathrm{DHEAS}}\;(\mu\mathrm{mol/L})=0.02714\times C_{\mathrm{DHEAS}}\;(\mu\mathrm{g/dL}).$$

Equivalently, 1 µmol/L is approximately 36.849 µg/dL. Thus 4.5–7 µmol/L corresponds to about 166–258 µg/dL, and 7–11 µmol/L to about 258–405 µg/dL. These are arithmetic examples, not recommended targets. Selecting the upper third of the young-adult range for every older person has not been validated as an outcome-based treatment strategy. Neither a lower-third age interval nor a cortisol:DHEA-S ratio above 0.10 establishes a universal need for therapy.

The original proposed companion stack included vitamin C, pantothenate, phosphatidylserine, ashwagandha, acetyl-L-carnitine and coenzyme Q10. Each has biological or experimental rationales in its own field, but those rationales do not establish restoration of the human zona reticularis, adrenal b5 activity, PAPS production or immune outcomes. Vitamin C is not the obligatory electron donor in the CYP17A1–POR system. Pantothenate's role in coenzyme A does not make it a PAPS substrate. A reduction in a stress measure with phosphatidylserine or ashwagandha does not prove correction of adrenopause. General mitochondrial roles of acetyl-L-carnitine and CoQ10 do not demonstrate that these products reverse an identified adrenal ATP defect. The listed combination doses therefore cannot be presented as an evidence-based endocrine protocol.

If DHEA is considered for a defined clinical reason, assessment concerns symptoms, steroid exposure, adverse effects and relevant underlying disease. Cancer screening should follow appropriate clinical guidance and individual risk, rather than an invented universal schedule of PSA fractions, imaging or six-month examinations for all supplement users. Monitoring a biochemical concentration is useful only alongside a justified treatment question and evidence of benefit.

What remains open

Human adrenal androgen physiology, local sulfation and desulfation, neuroactive actions and immune-cell responses remain important research subjects. Selective modulation of SULT2A1, STS or CYP17A1–b5 interactions is a mechanistic research possibility, not an available validated method of restoring youthful adrenal function. STS inhibition in hormone-dependent disease also illustrates why changing precursor availability can have consequences opposite to a simple “more is better” model.

DHEA-S links adrenal development, electron-transfer chemistry, sulfate activation, tissue transport and local sex-steroid metabolism. Its age trajectory and associations deserve careful study. Present evidence supports that biological importance while leaving broad claims of immune rejuvenation, longevity, dementia prevention and standardized anti-aging supplementation unproven.