Adrenal cortex

Adrenal Cortex (Glandular Extract): A Comprehensive Reference

1. Identity, Source, and Common Preparations

What It Is

Adrenal cortex supplements are dietary supplements made from the outer layer of adrenal glands taken from cows or pigs. They belong to a broader category of products known as glandulars, a subset of organotherapy. Adrenal glandulars are dietary supplements made from the desiccated (dried and powdered) adrenal glands of animals, most commonly cows (bovine) or pigs (porcine). These supplements are part of a broader category known as "glandular therapy," which uses animal organs or tissues to support the function of similar organs in humans.

The adrenal gland has two distinct parts. The outer layer, the cortex, produces steroid hormones: cortisol (the main stress hormone), aldosterone (which regulates blood pressure and electrolytes), and small amounts of sex hormones. The inner layer, the medulla, produces adrenaline and noradrenaline. Adrenal cortex supplements use only the outer layer, which means they should theoretically be free of adrenaline. By contrast, whole adrenal glandulars include both layers.

Source Animals and Anatomical Origin

The source animals are typically cattle or pigs. Adrenal extract is a chemical that is made from the adrenal glands of slaughtered cows, pigs, and sheep. The supplement derives exclusively from the cortical (outer) tissue of these glands. To understand what this tissue represents biologically: the adrenal cortex takes part in steroidogenesis, producing glucocorticoids, mineralocorticoids, and androgen precursors. It has three distinct functional and histological zones: the zona glomerulosa (outermost layer), the zona fasciculata (middle layer), and the zona reticularis (innermost layer).

Common Preparation Methods and Dosage Forms

The tissue is typically freeze-dried (lyophilized) rather than heat-processed, a crucial step that preserves the delicate enzymatic structures, peptides, and nucleoproteins that give the glandular extract its therapeutic potential. Freeze-dried (lyophilized) preparations preserve more of the natural nutrients; defatted preparations remove some fats.

Manufacturers dry and process the gland tissue into capsules, with commercial doses ranging from about 50 mg to 350 mg per capsule. It can be taken by mouth, placed under the tongue (used sublingually), or injected into the veins (given intravenously), though injectable forms are no longer legally available in the United States (see Safety section). Many products today are sold in vegetarian capsules using lyophilized bovine cortical tissue.

Adrenal cortex extract isolates just the outer part (cortex) and is sometimes preferred for those who want to avoid stimulating compounds from the medulla. Some formulations contain tissue from both the adrenal cortex and medulla with the intent to support healthy adrenal function, stress hormone balance, and immune regulation, but may also isolate adrenal cortex exclusively.

2. Traditional and Historical Use

Ancient and Pre-Modern Traditions

Animal glands have been valued as food and as medicine for millennia. Using the glands or other organs of animals for medicinal treatment, also called organotherapy, goes back to ancient medical times, part of the timeless phenomenon known as "like heals like." Traditionally, cultures around the world consumed organ meats to nourish those same organs in their own bodies.

19th-Century Organotherapy and the Emergence of Glandular Medicine

Dating back to the late 19th and early 20th centuries, organotherapy operates on the principle of "like supports like"—the theory that consuming the specific tissue of a healthy animal can provide targeted nutritional support, repair, and normalization to the corresponding organ in a human.

Glandular therapy was first taken seriously by physicians in the 19th century, when it was discovered that dried porcine thyroid gland could treat underactive thyroid and dried animal-based adrenal glands could treat Addison's disease. Before this, neither condition was controllable.

Medullary epinephrine was the first hormone to be isolated (in 1901), and numerous cortical steroids were isolated between 1930 and 1949. The treatment of arthritis, Addison's disease, and congenital adrenal hyperplasia (CAH) with cortisone in the 1950s revolutionized clinical endocrinology and steroid research.

Most famously (or infamously), in 1889 Charles-Edouard Brown-Séquard reported "rejuvenated sexual prowess" after injecting himself with testicular extracts. This was certainly a placebo effect, as recapitulation of Brown-Séquard's procedures yield a fluid with insignificant amounts of steroids. Brown-Séquard's "organotherapy" may have been quackery, but it inspired other research work.

Early 20th-Century Medical Use of Adrenal Cortex Extract

Early in the twentieth century, physicians used glandular extracts as an actual source of hormones. Glandular therapy dates back to the early 20th century and was initially used by physicians to treat various endocrine and metabolic disorders before the era of synthetic hormones.

In 1920, Muirhead, a pharmacology professor with Addison's disease, devised a treatment that required 1,200 mg of dried whole gland per day, orally, together with adrenaline injections. Muirhead was bedridden before beginning this treatment, improved substantially on it with clearing of his pigmentation, but after several months, deteriorated and died. In a series of patients treated at the Mayo Clinic in the 1920s, Rowntree et al. described the Muirhead method as being beneficial for half of the patients treated.

A preparation described as "1 part represents 5 parts fresh capsule" was recommended for the treatment of Addison's disease, hay fever, and neurasthenia. Clinicians used adrenal glandular material, raw or dried and formed into a tablet, to treat conditions such as asthma, with some success.

By the 1920s and 1940s, doctors recommended cortex extract for "hypoadrenal syndrome." It addressed symptoms like fatigue, nervousness, and low blood sugar. Patients reported relief from concentration issues and faintness.

It was noted by organotherapists that isolated hormones (such as adrenalin) were more effective in acute cases, while the whole gland (adrenals) were more effective in chronic conditions.

The basis for some recommended uses of adrenal extracts, such as allergies, asthma, and rheumatoid arthritis, was that these are conditions that respond to cortisone.

At one end of glandular therapy's spectrum, Mayo Clinic rheumatologist Philip S. Hench, MD, after decades of research, was awarded a Nobel Prize for his work with adrenal and pituitary hormones (extracted from animals).

Decline and Regulatory Shift

By the final decades of the 20th century, the development of synthetic hormones brought research using animal-based glandulars to a halt. Yet clinicians did agree that certain animal gland and organ preparations, when taken orally, were quite effective in treating a variety of conditions.

Once used to treat Addison's disease, adrenal gland extract was found to be low in potency and removed from the drug market in 1978 as synthetic medications became available. The U.S. Food and Drug Administration (FDA) barred imported adrenal extract in 1989. In 1996, it recalled injectable extracts. It also issued public warnings against the use of adrenal extract after discovering that more than 80 people developed infections from contaminated products. This pushed remaining products into the dietary supplement category.

The use of whole adrenal glandulars became more common in the mid-20th century, particularly during the rise of alternative medicine and nutritional supplementation. "Adrenal fatigue"—a controversial condition not recognized by mainstream medicine—became a term to describe chronic exhaustion and low energy resulting from stress and poor adrenal function. Adrenal glandular supplements were marketed as a natural solution to support the adrenal glands and improve symptoms of fatigue, low energy, and burnout, though the clinical evidence supporting these claims remains limited.

3. Anatomy of the Source Tissue: What the Adrenal Cortex Is

To properly evaluate adrenal cortex supplements, understanding the native biology of the source tissue is essential.

The adrenal glands are paired endocrine organs that play a vital role in maintaining homeostasis by regulating blood pressure, metabolism, electrolyte balance, and the body's response to stress. Each gland comprises the adrenal cortex, which produces steroid hormones, and the adrenal medulla, responsible for catecholamine synthesis. The cortex is further divided into three functional zones: the zona glomerulosa (mineralocorticoids), the zona fasciculata (glucocorticoids), and the zona reticularis (androgens), while the medulla secretes adrenaline, noradrenaline, and dopamine under sympathetic control.

More specifically: the adrenal cortex is further subdivided into three distinct functional zones: the zona glomerulosa (ZG), zona fasciculata (ZF), and zona reticularis (ZR). The ZG produces the mineralocorticoid aldosterone, primarily regulated by angiotensin II (AngII). The ZF synthesizes the glucocorticoid cortisol under the main control of adrenocorticotropic hormone (ACTH). The ZR secretes adrenal androgens also under the control of ACTH.

Adrenal cortex hormones are steroid molecules, which are derived from cholesterol through serial conversions catalyzed by specific enzymes, the "steroid hydroxylases" that belong to the cytochrome P450 (CYP) superfamily. This biochemical process is known as "adrenal steroidogenesis."

Adrenal cortex hormones bind onto specific steroid receptors that belong to the nuclear receptor superfamily of transcription factors. Glucocorticoids bind onto the glucocorticoid receptor (GR), mineralocorticoids signal through the mineralocorticoid receptor (MR), and adrenal androgens may bind onto the androgen receptor (AR), or, following aromatization, onto the estrogen receptor (ER).

4. Key Constituents and Putative Active Compounds

Steroid Hormones Naturally Present in Source Tissue

When bovine or porcine adrenal cortex tissue is processed into supplement form, the following classes of compounds are potentially present in the raw material, though their concentrations in finished products vary widely and are often not disclosed on labels:

• Glucocorticoids: Primarily cortisol (hydrocortisone), which is the primary glucocorticoid in cattle and humans alike.
• Mineralocorticoids: Aldosterone, which regulates sodium and potassium balance and blood pressure.
• Adrenal androgens: Dehydroepiandrosterone (DHEA) and androstenedione, precursor steroids produced by the zona reticularis.
• Steroid precursors: Pregnenolone, the upstream precursor molecule to all adrenal steroid hormones.

The concentration of cortisol in bovine adrenal gland is quite low, between 2 and 4 micrograms/gram. The product used in the Muirhead regimen, which generated clinical improvements and resolution of hyperpigmentation, could have had no more than 0.024 milligrams of cortisol. The extract made with 20 cows' worth of adrenal cortex could have had at most 3 milligrams of cortisol, probably less given inevitable losses in processing.

While some clinicians worry about adrenal suppression when they hear a patient has been taking adrenal glandular, the supplement can't contain enough corticosteroid to cause it. A 200 mg capsule would require roughly one gram of raw material to produce, containing only 4–5 micrograms of cortisol at native tissue concentrations.

Other Constituents Identified by Analytical Testing

A 2018 peer-reviewed analytical study published in Mayo Clinic Proceedings (Akturk et al.) directly measured hormone content in commercially available supplements. The objective was to assess whether dietary supplements that are herbal and/or animal-derived products, marketed for enhancing metabolism or promoting energy, "adrenal fatigue," or "adrenal support," contain thyroid or steroid hormones. Twelve dietary adrenal support supplements were purchased. Pregnenolone, androstenedione, 17-hydroxyprogesterone, cortisol, cortisone, dehydroepiandrosterone sulfate, synthetic glucocorticoids (betamethasone, dexamethasone, fludrocortisone, megestrol acetate, methylprednisolone, prednisolone, prednisone, budesonide, and triamcinolone acetonide) levels were measured twice in samples in a blinded fashion. The study was conducted between February 1, 2016, and November 1, 2016.

Specific findings: All the supplements revealed a detectable amount of triiodothyronine (T3) (63–394.9 ng/tablet), 42% contained pregnenolone (66.12–205.2 ng/tablet), 25% contained budesonide (119.5–610 ng/tablet), 17% contained androstenedione (1.27–7.25 ng/tablet), 8% contained 17-OH progesterone (30.09 ng/tablet), 8% contained cortisone (79.66 ng/tablet), and 8% contained cortisol (138.5 ng/tablet). Per label recommended doses, daily exposure was up to 1,322 ng for T3, 1,231.2 ng for pregnenolone, 1,276.4 ng for budesonide, 29 ng for androstenedione, 60.18 ng for 17-OH progesterone, 277 ng for cortisol, and 159.32 ng for cortisone.

The conclusion of the study was that all the supplements studied contained a small amount of thyroid hormone and most contained at least one steroid hormone. This was the first study that measured thyroid and steroid hormones in over-the-counter dietary "adrenal support" supplements in the United States. These results may highlight potential risks of hidden ingredients in unregulated supplements.

Non-Hormonal Compounds and the "Nutritional Matrix" Argument

Proponents of glandular therapy suggest that a high-quality adrenal cortex extract provides the exact biochemical building blocks—including specific nucleoproteins, lipid factors, and enzymatic precursors—that the human adrenal glands require to synthesize their own hormones efficiently.

Unlike a single synthesized vitamin, an adrenal cortex extract is a complex matrix of biological compounds. The human digestive system breaks down these tissues into their constituent amino acids, lipids, and trace minerals. However, proponents of organotherapy argue that certain tissue-specific peptides and nucleoproteins survive the digestive process intact, crossing the intestinal barrier via specialized transport mechanisms to exert targeted effects on the human adrenal glands.

5. Proposed Mechanisms of Action

The "Like Supports Like" Principle

The theory behind this practice, often called "like supports like," proposes that consuming healthy animal glands can help nourish and revitalize corresponding glands in the human body. This concept has been the cornerstone of organotherapy since the late 19th century but remains unvalidated by controlled mechanistic research.

Direct Hormone Delivery

Animal adrenal glands may contain significant levels of adrenal hormones. This is the basis for some recommended uses of adrenal extracts, such as allergies, asthma, and rheumatoid arthritis (conditions that respond to cortisone). However, modern adrenal extracts are manufactured so they do not contain significant levels of adrenal hormones. Therefore, it is difficult to find any justification for their use along these lines.

Oral Tolerance and Immune Downregulation (Theoretical)

When an antigenic substance is taken by mouth, the body's reaction to that antigen may downregulate. Because autoimmunity causes many of the problems related to glandular malfunction, taking glandular extracts orally might decrease autoimmunity and thereby improve glandular function. Trials of oral tolerance to autoantigens have met with mixed success in the past, but subsequent researchers speculated that this may be due to issues with the gut microbiome.

Nutritional Substrate Provision

A number of glandular preparations are effective orally because of active hormone or enzyme content (e.g., thyroid, adrenal cortex, and pancreatin preparations). Whether this applies meaningfully to modern adrenal cortex supplements—which manufacturers often claim are hormone-depleted—is disputed.

The digestive system breaks proteins down into amino acids; there is no established mechanism by which swallowed adrenal tissue would selectively nourish human adrenal glands. This critique reflects the consensus view in mainstream physiology: orally ingested proteins, peptides, and hormones are generally degraded in the gastrointestinal tract before they can exert organ-targeted effects.

6. Scientific Evidence by Area of Use

6.1 "Adrenal Fatigue" — The Primary Marketing Target

The condition most commonly cited as the rationale for using adrenal cortex supplements is "adrenal fatigue," described as a state of impaired adrenal output due to chronic stress. The term "adrenal fatigue" has been used by some doctors, healthcare providers, and the general media to describe an alleged condition caused by chronic exposure to stressful situations. Despite this, "adrenal fatigue" has not been recognized by any endocrinology society, who claim there is no hard evidence for the existence.

A 2016 systematic review by Cadegiani and Kater, published in BMC Endocrine Disorders, specifically addressed the evidence base for this condition. The review concluded that "this systematic review proves that there is no substantiation that 'adrenal fatigue' is an actual medical condition. Therefore, adrenal fatigue is still a myth." A 2016 systematic literature review of adrenal fatigue including data from 58 studies concluded that the studies were highly flawed, providing conflicting results and inappropriate conclusions.

The Endocrine Society, the leading professional organization for hormone specialists, has stated clearly that adrenal fatigue is not a recognized medical diagnosis. There is no validated test for it. Blood or saliva cortisol tests sometimes offered by alternative practitioners are not supported by good scientific evidence, and the results can be misleading. The symptoms commonly labeled as adrenal fatigue—including exhaustion, sleep problems, difficulty concentrating, and salt or sugar cravings—overlap with dozens of well-established conditions: thyroid disorders, sleep apnea, depression, iron deficiency, and actual adrenal insufficiency (Addison's disease), among others.

Evidence strength: No credible human clinical trials demonstrate that adrenal cortex supplements improve outcomes in individuals claiming "adrenal fatigue." The underlying diagnosis is not recognized by any major endocrinological or medical body. Evidence strength: none for this specific indication.

6.2 Chronic Fatigue, Stress, and Energy — General Population

There are no well-designed clinical trials showing that adrenal cortex supplements improve energy, reduce stress, or restore adrenal function in people without a diagnosed adrenal disease.

While some ingredients in adrenal support formulas have individually been shown to reduce fatigue or symptoms of stress, there is currently little evidence that "adrenal support formulas" do the same or improve adrenal gland function.

Evidence strength: Insufficient. No controlled human studies have been conducted specifically on adrenal cortex glandular extracts for fatigue or stress in otherwise healthy individuals.

6.3 Historical Use for Addison's Disease (Primary Adrenal Insufficiency)

Prior to the isolation and synthesis of cortisone and hydrocortisone, adrenal cortex extracts were the primary treatment for Addison's disease. In a series of patients treated at the Mayo Clinic in the 1920s, Rowntree et al. described the Muirhead method as being beneficial for half of the patients treated. These historical case series and clinical reports, while representing real therapeutic use at the time, predate modern controlled trial methodology.

Once used to treat Addison's disease, adrenal gland extract was found to be low in potency and removed from the drug market in 1978 as synthetic medications became available.

Evidence strength: Historical/observational only. Modern pharmaceutical-grade hydrocortisone and fludrocortisone have entirely superseded adrenal glandular products for Addison's disease. For people with confirmed adrenal insufficiency (a condition diagnosed through specific hormone testing by an endocrinologist), the standard treatment is prescription hormone replacement with precise, measured doses.

6.4 HPA Axis Dysregulation and Stress Adaptation

Some integrative and functional medicine practitioners propose adrenal cortex supplements as support for hypothalamic-pituitary-adrenal (HPA) axis dysregulation, particularly in the context of chronic stress, burnout, or post-viral conditions. The key to understanding this debilitating fatigue often lies in the HPA axis, the intricate communication network that governs the body's survival mechanisms. In the wake of severe viral infections or prolonged chronic stress, this delicate system can become dysregulated, leading to a state where the adrenal glands fail to produce adequate levels of essential hormones like cortisol. However, no controlled clinical trials have tested adrenal cortex glandular products specifically on objectively measured HPA axis outcomes in human subjects.

Evidence strength: Theoretical/anecdotal only. The proposed mechanism lacks human trial validation.

6.5 DHEA as a Constituent — Separate Evidence Base

DHEA (dehydroepiandrosterone), a natural product of the adrenal zona reticularis, is present in some adrenal cortex supplements and is also sold separately. While there are claims that pregnenolone is an effective anti-aging treatment, there are no studies to support its use for adrenal insufficiency or deficiency. DHEA is another endogenous precursor steroid that is mainly produced by the adrenal cortex, and supplements containing DHEA are often marketed to support adrenal health and increase energy. However, a systematic review of DHEA supplementation in postmenopausal women did not support an improvement in wellbeing with DHEA supplement use.

Evidence strength: Weak to mixed for DHEA as an isolated ingredient; evidence for DHEA as delivered within whole adrenal cortex glandulars is essentially absent.

6.6 Glandular Therapy Generally — PMC Review

A peer-reviewed historical review published in PMC (2023) that examined the history of thyroid, pancreatic, adrenal, thymus, and liver extracts concluded: the history of the use of thyroid, pancreatic, adrenal, thymus, and liver extracts suggests that glandular extracts can be beneficial, especially when potential mechanisms of action and methods of preparation are considered. This summary, however, does not constitute clinical trial evidence and pertains primarily to historical use and mechanistic plausibility rather than modern randomized controlled data.

7. Body Systems and Health Areas Associated with This Supplement

Based on the anatomical role of the source tissue and the claims made in the literature, adrenal cortex supplements are associated with the following body systems:

• Endocrine system / HPA axis: The adrenal glands are uniquely structured to support stress adaptation. Their two functional regions (the cortex and the medulla) coordinate distinct but complementary physiological processes, allowing the body to respond to both immediate and longer-term demands.
• Stress response and glucocorticoid signaling: Adrenal cortex tissue is associated with pathways involved in the synthesis of steroid hormones such as cortisol, aldosterone, and DHEA.
• Cardiovascular / electrolyte regulation: Aldosterone, the mineralocorticoid produced by the zona glomerulosa, helps in the regulation of blood pressure and electrolyte balance.
• Immune system: Glucocorticoids produced by the adrenal cortex are well-established modulators of immune function. Some formulations are marketed for immune regulation on this basis.
• Metabolic function: Cortisol plays roles in glucose metabolism, protein catabolism, and fat mobilization, which is why some formulations are marketed for metabolic support.
• Sex hormone precursor pathways: The zona reticularis produces androgen precursors, mostly DHEA with some androstenedione.

8. Dosage Forms and Dosages Reported

Manufacturers dry and process the gland tissue into capsules, with commercial doses ranging from about 50 mg to 350 mg per capsule.

Specific dosages reported in available sources:

• Thorne Adrenal Cortex: One capsule contains Adrenal Cortex (Bovine) 50 mg. Other ingredients: Microcrystalline Cellulose, Hypromellose (derived from cellulose) capsule, Silicon Dioxide.
• Historical Muirhead regimen (1920s, Addison's disease): 1,200 mg of dried whole gland per day, orally, together with adrenaline injections.
• General supplement label instructions: 1 capsule daily with food or as directed by a healthcare professional.

Supplement labels do not list their potency or how much of each adrenal hormone they contain. This is a fundamental limitation: unlike pharmaceutical preparations, there is no standardized potency specification for adrenal cortex dietary supplements, meaning that milligram doses of "adrenal cortex" across different brands are not equivalent.

9. Safety Considerations and Notable Risks

Presence of Undisclosed Hormones

This is the most rigorously documented safety concern. A study that tested 12 over-the-counter adrenal support supplements containing glandular extracts found that all 12 contained thyroid hormones and 58% contained steroid hormones. These are bioactive compounds that can affect the body in ways one would not expect from a supplement. Taking hidden thyroid or steroid hormones without medical supervision poses real health risks, including disrupting one's own hormone production.

Many brands claim their products are "hormone-free," but that claim doesn't hold up well under testing. Supplements are classified as food products, not medicines; therefore, they are not subject to the strict regulatory standards of the FDA.

Risk of Iatrogenic Adrenal Suppression and Cushing's Syndrome

If a supplement delivers enough cortisol or cortisol-like compounds over time, the body's own cortisol production can shut down. Stopping the supplement suddenly could then trigger genuine adrenal insufficiency, a condition where the body can't produce enough cortisol on its own. In some cases, prolonged hidden steroid exposure has led to Cushing syndrome, a condition marked by weight gain, high blood sugar, weakened bones, and a characteristic rounding of the face.

The potential complications of unsupervised and unknown exposure to steroid hormones include development of iatrogenic Cushing syndrome and a risk for adrenal insufficiency if these supplements are discontinued abruptly. Furthermore, the use of these supplements may delay the diagnosis and treatment of medical issues and can also worsen pre-existing medical conditions.

The U.S. FDA has issued multiple warnings regarding dietary supplements and conventional foods found to contain undisclosed pharmaceutical ingredients. A 2016 study evaluating 12 over-the-counter "adrenal support" supplements in the United States found that most contained at least one steroid hormone.

Label Inconsistency and Dose Unpredictability

Because the actual hormone content of any given product is unknown, the side effect profile is essentially unpredictable. Two capsules from different brands, both labeled "adrenal cortex 250 mg," could contain very different amounts of active hormones.

Over-the-counter glandulars are not a substitute for prescription hormone replacement because their hormone content is neither consistent nor predictable.

Bovine Spongiform Encephalopathy (BSE) / Prion Risk

Because glandular supplements are made from animal organs, there are valid historical concerns regarding the transmission of animal-borne pathogens, such as Bovine Spongiform Encephalopathy (BSE). To mitigate these risks, reputable nutraceutical companies source their bovine tissue exclusively from countries with strict agricultural regulations and documented BSE-free statuses, such as Argentina. However, because these are dietary supplements rather than drugs, the FDA does not require manufacturers to prove they work or to verify the exact hormone content before selling them. There is no standardized testing protocol that guarantees a product is truly hormone-free.

Historical Safety Incidents with Injectable Forms

The U.S. Food and Drug Administration (FDA) barred imported adrenal extract in 1989. In 1996, it recalled injectable extracts. It also issued public warnings against the use of adrenal extract after discovering that more than 80 people developed infections from contaminated products. There were also safety concerns with injectable and imported adrenal gland extracts.

Potential Interference with Diagnostic Testing

An analysis of popular adrenal support supplements on the market found that all contained small amounts of thyroid and steroid hormones, which could potentially cause adverse effects or interfere with blood test results. This is a clinically meaningful consideration: patients taking these supplements who undergo cortisol, thyroid, or other endocrine laboratory testing may receive distorted results.

Concerns Specific to Diagnosis Delay

The symptoms commonly labeled as adrenal fatigue—including exhaustion, sleep problems, difficulty concentrating, and salt or sugar cravings—overlap with dozens of well-established conditions: thyroid disorders, sleep apnea, depression, iron deficiency, and actual adrenal insufficiency (Addison's disease), among others. The concern from endocrinologists is that accepting an unproven diagnosis delays the identification of something treatable.

Regulatory and Quality-Control Context

Supplements are classified as food products, not medicines; therefore, they are not subject to the strict regulatory standards of the FDA. A position statement by the American Association of Clinical Endocrinologists (AACE), published in Endocrine Practice, is aimed at raising awareness in the medical community about the risks of off-label use and misuse of hormones and dietary supplements. These products are usually advertised as safe despite limited or no data to support their efficacy or safety, and they are often taken without the supervision of a healthcare provider.

10. Summary of Evidence Quality

The following table summarizes the overall state of evidence as derived from available authoritative sources:

• Historical therapeutic use (Addison's disease, asthma, neurasthenia): Well-documented historically in early 20th-century clinical reports, but superseded by modern pharmaceuticals. Evidence quality: historical case series only.
• "Adrenal fatigue" treatment: No credible human clinical trials exist. The underlying condition is not recognized by any endocrinology society. A systematic review (Cadegiani & Kater, BMC Endocrine Disorders, 2016) found no substantiation for the syndrome or its treatment with supplements.
• Fatigue, energy, and stress in otherwise healthy people: No controlled human trials specifically on adrenal cortex glandular extracts have been published.
• Hormone content and bioactivity: Confirmed by peer-reviewed analytical chemistry (Akturk et al., Mayo Clinic Proceedings, 2018) — products contain measurable steroid hormones, but at generally low and highly variable amounts.
• Mechanisms of action: Unvalidated in controlled human research. Proposed mechanisms (nutritional substrate provision, oral tolerance, direct hormone delivery) remain theoretical or contradicted by basic physiology.
• Safety signals: Supported by documented FDA regulatory actions (1989, 1996), peer-reviewed hormone-content analysis (2018), and published case reports of iatrogenic endocrine disruption from supplement-derived steroid exposure.

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