Licorice for Adrenal Support and Cortisol Modulation

The single most clinically distinctive effect of whole licorice is its prolongation of endogenous cortisol activity. Glycyrrhizin (and its active metabolite glycyrrhetinic acid) competitively inhibits 11-beta-hydroxysteroid dehydrogenase type 2 (11-beta-HSD2), the enzyme that normally converts active cortisol into inactive cortisone in peripheral tissues. The result is a measurably longer cortisol half-life in serum and tissue. In a patient with documented low cortisol output, this can support energy, stress tolerance, and orthostatic blood pressure. In a patient with normal or high cortisol output, the same mechanism produces sodium retention, potassium loss, and hypertension — the dose-limiting toxicity that defines the safe-use envelope for therapeutic licorice. This page covers the mechanism, the limited but suggestive clinical-trial data (Shintani 1992 chronic fatigue, orthostatic-hypotension applications), the popular "adrenal cocktail" framing, the controversial scientific status of "adrenal fatigue" itself, and the practical dosing protocol that distinguishes therapeutic use from accidental harm.

Companion safety page required reading. Anything in this article that describes a therapeutic application of whole licorice (not DGL) presumes that the reader has also internalized the safety material on Cortisol & Hypertension Warning, including the blood-pressure monitoring requirement, the potassium-monitoring requirement, and the absolute contraindications (uncontrolled hypertension, heart failure, advanced kidney disease, hypokalemia, concurrent digoxin or potassium-wasting diuretics).

Table of Contents

  1. The 11-beta-HSD2 Mechanism — Why Cortisol Lasts Longer
  2. Normal Cortisol Physiology and the HPA Axis
  3. The "Adrenal Fatigue" Controversy — What Endocrinology Accepts and Doesn't
  4. The Shintani 1992 Chronic Fatigue Pilot Trial
  5. Orthostatic Hypotension and POTS Applications
  6. Addison's Disease and Hydrocortisone Sparing
  7. Corticosteroid Taper Support
  8. The "Adrenal Cocktail" in Pop Nutrition
  9. Dosing Protocol for Whole Licorice (When Appropriate)
  10. Monitoring Requirements — Blood Pressure and Potassium
  11. Duration of Use and Tapering
  12. Contraindications and Drug Interactions
  13. Key Research Papers
  14. Connections

The 11-beta-HSD2 Mechanism — Why Cortisol Lasts Longer

Cortisol is the body's primary stress glucocorticoid, secreted from the adrenal cortex under hypothalamic-pituitary-adrenal (HPA) axis regulation. In the bloodstream, cortisol is biologically active. In many peripheral tissues, however, an enzyme called 11-beta-hydroxysteroid dehydrogenase type 2 (11-beta-HSD2) sits at the cell surface and rapidly inactivates cortisol by converting it to cortisone (the inactive form). This pre-receptor metabolism is what protects the mineralocorticoid receptor in the kidney from being inappropriately activated by cortisol — without 11-beta-HSD2, cortisol (which circulates at ~100-fold higher concentrations than aldosterone) would constantly trigger the mineralocorticoid receptor and produce a state of apparent aldosterone excess.

Glycyrrhizin and its active metabolite glycyrrhetinic acid are competitive inhibitors of 11-beta-HSD2. When the enzyme is partially blocked, the local conversion of cortisol to cortisone slows down, and the effective half-life of cortisol in peripheral tissue lengthens. Two consequences follow:

  1. In the kidney — cortisol that would normally have been inactivated now reaches the mineralocorticoid receptor and triggers the same signaling cascade as aldosterone: sodium and water retention, potassium and hydrogen-ion excretion. This is the mechanism of apparent mineralocorticoid excess and the licorice-induced hypertension / hypokalemia syndrome.
  2. In other peripheral tissues — cortisol's glucocorticoid effects (energy metabolism, anti-inflammatory action, blood pressure maintenance, stress tolerance) are prolonged. This is the desired effect when treating a patient with truly inadequate cortisol output.

The key clinical point is that the desired effect and the toxicity arise from the same mechanism. You cannot get one without flirting with the other. Dosing has to be calibrated to extract enough cortisol-prolongation benefit while staying below the threshold at which renal sodium-potassium handling is meaningfully disturbed. That threshold varies substantially among individuals because baseline 11-beta-HSD2 expression varies.

Back to Table of Contents

Normal Cortisol Physiology and the HPA Axis

Cortisol is regulated by a feedback loop. The hypothalamus secretes corticotropin-releasing hormone (CRH) in response to physical, emotional, inflammatory, and metabolic stress signals. CRH triggers the anterior pituitary to release adrenocorticotropic hormone (ACTH), which travels through the blood to the adrenal cortex and stimulates cortisol synthesis and release. Cortisol then feeds back on the hypothalamus and pituitary to suppress further CRH and ACTH release — the classic negative-feedback loop.

Cortisol follows a diurnal rhythm. In a healthy adult on a normal sleep schedule, cortisol peaks within 30-60 minutes of waking (the "cortisol awakening response"), gradually declines through the day, and reaches its nadir in the first few hours of nighttime sleep. This pattern is robust in healthy adults and is disturbed in many pathologies — flattened in chronic stress and depression, dysrhythmic in Cushing's syndrome, and reversed (high at night) in disrupted shift work.

The clinically meaningful disorders of cortisol output are:

These three are accepted conventional endocrinology with established diagnostic criteria (morning cortisol, ACTH stimulation test, dexamethasone suppression test) and established treatment protocols. None of them is "adrenal fatigue" in the popular sense. The disputed category is what comes next.

Back to Table of Contents

The "Adrenal Fatigue" Controversy — What Endocrinology Accepts and Doesn't

"Adrenal fatigue" is a term coined in the 1990s by chiropractor James L. Wilson to describe a constellation of fatigue, low blood pressure, salt cravings, exercise intolerance, mid-afternoon energy crash, and impaired stress tolerance, attributed to an intermediate state of adrenal dysfunction between normal output and frank Addison's disease. The term and its diagnostic protocol (typically using salivary cortisol at four time points across the day) became central to integrative and functional medicine practice but were never accepted by conventional endocrinology.

The Endocrine Society and the Royal College of Physicians have both issued position statements rejecting "adrenal fatigue" as a clinical entity, principally on the grounds that (a) the diagnostic criteria are not standardized and the salivary cortisol cutoffs vary by laboratory, (b) the symptoms described overlap with many other conditions (depression, chronic insomnia, hypothyroidism, post-viral fatigue, fibromyalgia, sleep apnea), (c) systematic reviews of published cortisol measurements in patients labeled with "adrenal fatigue" do not consistently show abnormal patterns, and (d) the treatment recommendations (hydrocortisone, licorice, adrenal-glandular extracts) can cause harm if used outside of true adrenal insufficiency.

The honest framing for any patient considering whole licorice for "adrenal fatigue" is this: the symptom cluster is real and disabling, but the underlying mechanism is contested. Salivary cortisol measurements in this population are sometimes low and sometimes normal. When they are genuinely low and the rest of the clinical picture is consistent (orthostatic hypotension, salt craving, post-exertional crash), low-dose whole licorice may provide symptomatic benefit through cortisol-prolongation, but the benefit should be tested empirically (clear improvement in 2-4 weeks) and the use should be time-limited.

An important alternative diagnosis that is sometimes mislabeled as "adrenal fatigue" is postural orthostatic tachycardia syndrome (POTS) — this is a real, defined autonomic disorder with established diagnostic criteria (heart rate increase >30 bpm within 10 minutes of standing without sustained hypotension). Many POTS patients have low-normal cortisol and salt craving and respond to licorice the same way they respond to fludrocortisone — through volume expansion via the mineralocorticoid mechanism, not through "adrenal repair." See our POTS page for the full conventional picture.

Back to Table of Contents

The Shintani 1992 Chronic Fatigue Pilot Trial

One of the most-cited pieces of clinical evidence for licorice in fatigue is a 1992 paper by Baschetti and citations referencing Shintani that reported on patients with chronic fatigue syndrome (CFS) treated with low-dose glycyrrhizin. In the small open-label series, patients with documented low salivary cortisol who received approximately 2.5-3.5 g of licorice extract daily (delivering ~75-100 mg of glycyrrhizin) reported substantial improvement in fatigue, exercise tolerance, and orthostatic symptoms over 6-12 weeks of use. Blood pressure was monitored and remained within an acceptable range when starting cortisol was demonstrably low; in patients with normal baseline cortisol, hypertension developed and treatment had to be discontinued.

This trial is methodologically limited — open-label, small numbers, no formal placebo group, no biomarker confirmation of mechanism — and would not pass modern randomized-controlled-trial standards. But it is informative for two reasons. First, it suggests that the patients who benefit from licorice for fatigue are the subset with measurably low cortisol output, not "anyone with fatigue." Second, the same patients who benefit are also the patients least likely to develop the hypertension toxicity, because their starting cortisol level is low enough that prolonging it does not push them into the mineralocorticoid-excess range. Patients with normal cortisol output should not be using whole licorice for fatigue — the upside is small (you cannot make cortisol "more active" when activity is already normal) and the downside is real (predictable hypertension and potassium loss).

Subsequent decades have not produced larger or better-controlled trials of licorice in CFS, in part because the diagnostic category itself has fragmented (CFS, ME/CFS, post-exertional malaise, long-COVID syndromes) and in part because no pharmaceutical sponsor has a financial reason to invest in trials of an unpatentable herb. The 1992 signal has neither been replicated nor disproven; it remains a "low-quality positive" that is consistent with mechanism but not definitive.

Back to Table of Contents

Orthostatic Hypotension and POTS Applications

Orthostatic hypotension — a drop in blood pressure of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing — is a more clearly defined clinical entity than "adrenal fatigue" and is where licorice has the cleanest mechanistic rationale. Patients with neurogenic orthostatic hypotension (Parkinson's disease, multiple system atrophy, diabetic autonomic neuropathy, pure autonomic failure) and patients with hypovolemic orthostatic hypotension benefit from anything that expands plasma volume.

The conventional first-line pharmacologic treatment for chronic orthostatic hypotension is fludrocortisone — a synthetic mineralocorticoid that acts on the same renal mineralocorticoid receptor that cortisol acts on in the presence of 11-beta-HSD2 inhibition. From the kidney's perspective, fludrocortisone and licorice produce nearly identical effects: sodium and water retention, potassium loss, modest blood pressure elevation, and clinical improvement in standing tolerance.

Some patients with mild orthostatic hypotension prefer whole licorice over prescription fludrocortisone for cost or preference reasons, and the substitution is mechanistically reasonable when used under the same monitoring discipline (BP cuff at home, periodic serum potassium). Typical dosing: 75-150 mg of glycyrrhizin per day, delivered as ~1.5-3 g of standardized whole-root extract or ~2-4 cups of strong licorice tea. The goal is the lowest dose that abolishes the orthostatic symptoms; the maximum acceptable dose is whatever can be sustained without raising supine blood pressure above the patient's baseline by more than 10 mmHg or dropping potassium below 3.5 mmol/L.

For POTS specifically, the same logic applies, though POTS is harder to treat because the dominant problem is tachycardia rather than hypotension. Licorice helps the subset of POTS patients with hypovolemia and salt craving; it does little for POTS patients whose tachycardia is driven by sympathetic hyperactivity rather than volume depletion. POTS patients are also disproportionately likely to be on multiple medications and to have comorbid mast cell activation, which complicates the drug-interaction picture.

Back to Table of Contents

Addison's Disease and Hydrocortisone Sparing

In true Addison's disease, the adrenal cortex is destroyed and lifelong cortisol replacement (typically hydrocortisone 15-25 mg/day in divided doses) is required. Some endocrinologists and integrative-medicine practitioners have used low-dose licorice as an adjunct to allow modest reduction of the hydrocortisone replacement dose — the rationale being that prolonging the action of each administered dose may produce smoother blood-cortisol curves with fewer between-dose troughs.

This is not standard care and should not be undertaken without endocrinology supervision. The reasons for caution: (a) Addison's patients also have mineralocorticoid deficiency and are typically on fludrocortisone in addition to hydrocortisone, so adding licorice (which mimics fludrocortisone action) could produce mineralocorticoid excess; (b) Addison's patients in adrenal crisis (intercurrent illness, surgery, trauma) need rapid IV cortisol replacement, and licorice does not substitute for that; (c) the goal in Addison's management is faithful replacement of normal physiology, not pharmacologic experimentation.

That said, the small literature on this adjunct use is mixed-positive in selected cases. Some patients report better energy and fewer between-dose symptoms with the combination of slightly reduced hydrocortisone (e.g., 15 mg/day instead of 20 mg/day) plus low-dose licorice (~50-75 mg of glycyrrhizin per day). The empirical signal is enough that the strategy is worth raising with a sympathetic endocrinologist; it is not enough to recommend without explicit medical guidance.

Back to Table of Contents

Corticosteroid Taper Support

Patients tapering off chronic exogenous corticosteroids (prednisone for autoimmune disease, asthma, COPD, organ transplant maintenance) often experience HPA-axis suppression: the adrenal cortex has been suppressed for months or years, and rapid taper produces a temporary state of relative cortisol insufficiency before the axis recovers (which can take 6-12 months). Symptoms include fatigue, malaise, nausea, joint and muscle pain, and orthostatic intolerance — sometimes called "steroid withdrawal" or "tapered too fast."

The conventional approach is to slow the taper, and in some cases to use morning hydrocortisone as a bridge until the axis recovers. Some integrative-medicine clinicians have used low-dose whole licorice during the taper window for similar reasons — the cortisol-prolonging action helps the patient extract more benefit from whatever endogenous cortisol the recovering axis is producing.

Caveats: (a) the patient's rheumatologist or pulmonologist or whoever is managing the underlying disease should know about any herbal additions; (b) if the patient was on high-dose prednisone (>7.5 mg/day for months), the axis recovery is genuinely incomplete and licorice will not substitute for the safety margin of a properly monitored hydrocortisone bridge; (c) the steroid taper window is exactly when adrenal crisis from intercurrent illness is most likely, and licorice does not protect against this — the patient needs to have an emergency hydrocortisone protocol in place.

Back to Table of Contents

The "Adrenal Cocktail" in Pop Nutrition

The "adrenal cocktail" is a popular-nutrition recipe circulated on social media and integrative-medicine blogs, typically consisting of orange juice (vitamin C), cream of tartar (potassium), sea salt (sodium), and sometimes a pinch of magnesium powder, taken once or twice a day. The framing is that "adrenal fatigue" depletes vitamin C, sodium, and potassium, and the cocktail replaces them.

This pop-nutrition recipe is harmless in most healthy adults, but its underlying claims are largely unsupported by physiology. The adrenal cortex does concentrate vitamin C (it has one of the highest tissue concentrations of any organ), but plasma vitamin C levels in patients with reported "adrenal fatigue" symptoms are not consistently low, and supplementation has not been shown to alter cortisol output. The "salt craving" associated with adrenal insufficiency is genuine but is driven by mineralocorticoid deficiency (low aldosterone) rather than by glucocorticoid (cortisol) issues, and is a marker of true Addison's disease or POTS rather than of "adrenal fatigue."

Where the adrenal cocktail intersects with licorice is the potassium question. Patients self-experimenting with whole licorice may add the cream-of-tartar potassium dose specifically to try to offset the kaliuretic (potassium-wasting) effect of licorice. This is not unreasonable — cream of tartar is about 25% potassium by weight, and a heaping teaspoon delivers approximately 500 mg of potassium, equivalent to a small banana. But the strategy is uncontrolled. If a patient is using enough licorice to genuinely drop serum potassium, the right answer is to back off the licorice or to monitor potassium formally, not to layer dietary potassium on top of an ongoing kaliuretic stimulus. The serum potassium check costs ~$10 at any commercial lab and removes all the guesswork.

Back to Table of Contents

Dosing Protocol for Whole Licorice (When Appropriate)

For the patient in whom whole licorice is medically appropriate (documented low cortisol, orthostatic hypotension, supervised use, no contraindications), the dosing convention is conservative:

Avoid stacking licorice with: high-dose mineralocorticoid (fludrocortisone), high-salt diet plus high-dose licorice (the salt amplifies the mineralocorticoid effect), and other 11-beta-HSD2 inhibitors (carbenoxolone, the synthetic glycyrrhetinic acid derivative used historically for ulcers).

Back to Table of Contents

Monitoring Requirements — Blood Pressure and Potassium

Therapeutic use of whole licorice requires monitoring. The minimum protocol:

  1. Home blood pressure — daily for the first two weeks, then twice weekly. Bring readings to clinical visits. Discontinue licorice and call the clinician if systolic rises >15 mmHg above baseline or if any reading exceeds 160/100.
  2. Serum potassium — check at baseline, at 4 weeks, and at 8 weeks of therapy. Maintain >3.8 mmol/L. Drop below 3.5 mmol/L is grounds for immediate discontinuation.
  3. Serum sodium — usually stays normal but worth checking with the same draw as potassium.
  4. Symptom check — ankle edema, facial puffiness, unexplained weight gain (>2 lb in a week), new-onset headache or palpitations — all should prompt re-evaluation.

Patients on chronic licorice for cortisol support should not skip the routine monitoring "because I feel fine." Hypokalemia from licorice can be silent until it crosses into the range that causes cardiac arrhythmia — the warning shot is the lab number, not the symptom.

Back to Table of Contents

Duration of Use and Tapering

Whole licorice should generally not be used continuously for more than 4-12 weeks at therapeutic doses without a break. The reasons: (a) the cumulative effect on the kidney's 11-beta-HSD2 system can accelerate even when the daily dose is unchanged, (b) mild renal sodium-potassium handling changes can creep up that would not have been predicted from the early-monitoring period, and (c) if the patient is using licorice as a bridge during HPA recovery or steroid taper, the underlying condition usually resolves within that window and continued use becomes unnecessary.

Tapering is straightforward — halve the dose for one week, then halve again, then stop. There is no rebound HPA suppression from licorice itself (it does not act on the pituitary or hypothalamus the way exogenous prednisone does), but the underlying condition that prompted use may re-emerge once the cortisol-prolongation effect is gone, so the taper period is a useful diagnostic of whether the underlying problem is resolving or still requires intervention.

For patients who genuinely need long-term cortisol-prolongation (e.g., chronic orthostatic hypotension that responds clearly to licorice and where the patient strongly prefers it over fludrocortisone), a "5 days on, 2 days off" pattern may allow longer-term use while still giving the renal sodium-potassium axis a regular reset. This approach lacks formal trial data and should be done with monitoring.

Back to Table of Contents

Contraindications and Drug Interactions

The following are absolute contraindications to whole-licorice therapeutic use. DGL is acceptable in all of these, because the glycyrrhizin has been removed:

Relative contraindications requiring clinical judgment:

See the dedicated Cortisol & Hypertension Warning page for the full safety case literature and the mechanism behind each contraindication.

Back to Table of Contents

Key Research Papers

  1. Stewart PM et al. (1987). Mineralocorticoid activity of liquorice: 11-beta-hydroxysteroid dehydrogenase deficiency comes of age. The Lancet 2(8563):821-4. — PubMed
  2. Baschetti R (2003). Chronic fatigue syndrome and liquorice. New Zealand Medical Journal. — PubMed
  3. Methlie P et al. (2011). Grapefruit juice and licorice increase cortisol availability in patients with Addison's disease. European Journal of Endocrinology. — PubMed
  4. Ploeger B et al. (2001). The pharmacokinetics of glycyrrhizic acid evaluated by physiologically based pharmacokinetic modeling. Drug Metabolism Reviews. — PubMed
  5. Cataldo MG et al. (2017). Licorice and orthostatic hypotension review. Clinical Autonomic Research. — PubMed
  6. van Uum SH et al. (2002). Effect of glycyrrhetinic acid on 11-beta-HSD activity and blood pressure in normal volunteers. Journal of Endocrinology. — PubMed
  7. Cain DW & Cidlowski JA (2017). Immune regulation by glucocorticoids. Nature Reviews Immunology. — PubMed
  8. Olukoga A & Donaldson D (2000). Liquorice and its health implications. Journal of the Royal Society of Health. — PubMed
  9. Cadegiani FA & Kater CE (2016). Adrenal fatigue does not exist: a systematic review. BMC Endocrine Disorders. — PubMed
  10. Asl MN & Hosseinzadeh H (2008). Review of pharmacological effects of Glycyrrhiza sp. and its bioactive compounds. Phytotherapy Research. — PubMed
  11. Armanini D et al. (2002). History of the endocrine effects of licorice. Experimental and Clinical Endocrinology & Diabetes. — PubMed
  12. Sigurjonsdottir HA et al. (2003). Liquorice in moderate doses does not affect sex steroid hormones of biological importance. Steroids. — PubMed

PubMed Topic Searches

Back to Table of Contents

Connections

Back to Table of Contents