Licorice Root and Cortisol: The Adaptogen That Raises Blood Pressure (and Why Glycyrrhizin Matters)

If you're looking at licorice root as a cortisol adaptogen, you're examining one of the more genuinely complicated herbs in this category. Licorice root can increase cortisol activity in tissues, which is exactly why it appears in adrenal-fatigue formulas and exactly why it has sent people to the hospital with severe hypertension, cardiac arrhythmias, and dangerously low potassium. This article breaks down the glycyrrhizin mechanism, explains why DGL licorice is a completely different product, walks through the documented case reports, and gives you the drug-interaction picture that most herbal supplement articles skip. You'll also get the WHO safety threshold for glycyrrhizin, which almost no supplement label references, and an honest assessment of who has any business taking this herb.

Summary: quick answer on licorice root and cortisol

Licorice root raises cortisol availability in tissues through a specific enzyme-blocking mechanism. That can be useful in theory for people with depleted cortisol. In practice, the risks are serious enough that this herb should be treated differently from other adaptogens.

Best for: Very narrow clinical contexts under physician supervision, such as confirmed adrenal insufficiency managed by an endocrinologist. This is not a general-stress adaptogen.

Not ideal for: Anyone with hypertension, kidney disease, heart failure, cardiac arrhythmia, low potassium (hypokalemia), or anyone taking antihypertensives, diuretics, corticosteroids, digoxin, or MAOIs. Not for pregnancy. Not for people who buy adaptogens and self-dose.

What to look at before buying: The glycyrrhizin content. Most supplement labels don't disclose it. If the label says "standardized to 18% glycyrrhizin," that's a high-glycyrrhizin product with serious risk. DGL (deglycyrrhizinated licorice) has glycyrrhizin removed and is used for GI purposes, not cortisol effects.

Decision shortcut: If your reason for considering licorice root is stress or adrenal fatigue, there are better-evidenced and safer adaptogens. If you're considering it for GI support, use DGL, which has the dangerous compound removed. If you're considering whole licorice for cortisol support, consult an endocrinologist first.

What you'll find in this guide

• The glycyrrhizin mechanism: how licorice affects cortisol
• What the research actually shows
• DGL versus whole licorice: a critical distinction
• Who should not take licorice root
• Dosing context and the WHO safety threshold
• Side effects, case reports, and drug interactions
• Product context and what to look for
• Frequently asked questions
• Related reading

The glycyrrhizin mechanism: how licorice affects cortisol {#glycyrrhizin-mechanism}

Licorice (Glycyrrhiza glabra, family Fabaceae) is a plant native to the Mediterranean, western Asia, and parts of China. Its root contains glycyrrhizin, a triterpenoid saponin that is responsible for the herb's characteristic sweetness and its pharmacological effects on cortisol metabolism. In traditional Ayurvedic and Unani medicine, licorice root has been used for centuries as a tonic and anti-inflammatory agent. That traditional history is context, not evidence.

The mechanism is specific and well-characterized: glycyrrhizin and its primary metabolite glycyrrhizinic acid inhibit the enzyme 11-beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2). This enzyme normally converts active cortisol into inactive cortisone in peripheral tissues, particularly in the kidneys. When 11β-HSD2 is blocked, cortisol remains active longer in those tissues instead of being deactivated.

Think of it like a brake on a car that prevents cortisol from decelerating. Normally, cortisol zooms through kidney tissue and 11β-HSD2 applies the brake, converting it to cortisone so it doesn't chronically activate mineralocorticoid receptors there. Glycyrrhizin disables that brake. The result is cortisol flooding mineralocorticoid receptors in the kidney, mimicking the effect of excess aldosterone: the body retains sodium, loses potassium, and blood pressure rises.

This is what the supplement industry calls "cortisol support" or "adrenal support" in licorice-containing products. What they're describing is enzyme inhibition that extends cortisol's active lifespan in tissues, which is not the same as raising serum cortisol in a way that restores depleted adrenal function. The distinction matters for how you should read the marketing.

Per Memorial Sloan Kettering's integrative medicine database on licorice root, glycyrrhizin's mineralocorticoid activity is well-established in the pharmacological literature and underlies most of the safety concerns about chronic licorice use.

What the research actually shows {#what-research-shows}

The research on licorice root and cortisol is not organized around stress-reduction RCTs the way ashwagandha research is. The evidence base is primarily pharmacological studies documenting the 11β-HSD2 inhibition mechanism, human studies on chronic glycyrrhizin exposure and its metabolic effects, and a substantial collection of case reports documenting adverse outcomes.

Pharmacological studies confirming the mechanism

A foundational study by Quinkler and Stewart (2003), published in the Journal of Endocrinology (PMID 12615998), characterized glycyrrhizin's inhibition of 11β-HSD2 in human kidney cell models and confirmed the mechanism linking glycyrrhizin exposure to mineralocorticoid receptor activation. Earlier work by Stewart et al. (1990, PMID 2179754) in human subjects demonstrated that ingesting 100g of licorice candy daily for 9 days produced measurable suppression of plasma renin activity and aldosterone, consistent with 11β-HSD2 inhibition causing pseudo-aldosterone excess.

A 1999 dose-response study by van Uum and colleagues (PMID 10479175) showed that the blood pressure effects of glycyrrhizin in healthy volunteers were dose-dependent, appearing at daily intakes as low as 100mg glycyrrhizin and escalating with higher doses. This is the dose range that casual licorice confection consumption can reach, let alone concentrated supplement capsules.

Human studies on adrenal insufficiency claims

There is no robust RCT evidence that licorice root effectively treats adrenal fatigue as understood in the integrative medicine community. The NCCIH licorice fact sheet notes that while animal and mechanistic studies confirm 11β-HSD2 inhibition, human clinical trials on adrenal outcomes in stressed-but-otherwise-healthy adults are sparse. Most "adrenal fatigue" use of licorice root is extrapolation from the mechanism, not from controlled clinical data in that population.

The closest clinical context where glycyrrhizin's cortisol-extending effect has a legitimate rationale is in confirmed adrenal insufficiency (Addison's disease), where cortisol production is genuinely deficient and extending its activity could theoretically help. Even here, this is not standard medical treatment and would require physician oversight.

Actionable takeaway: The mechanism by which licorice root affects cortisol is real and well-documented. The clinical evidence that this translates into safe, effective "adaptogen" use for chronic stress in healthy people does not exist at an RCT level.

DGL versus whole licorice: a critical distinction {#dgl-vs-whole-licorice}

Deglycyrrhizinated licorice (DGL) is licorice root extract that has had glycyrrhizin removed, typically to below 2% of the extract by weight or less. DGL is sold widely for gastrointestinal applications, particularly for peptic ulcer support and relief from gastroesophageal reflux.

Because the glycyrrhizin is removed, DGL does not inhibit 11β-HSD2. It does not raise blood pressure through mineralocorticoid excess. It does not cause potassium depletion. The entire safety risk profile associated with whole licorice root is tied to glycyrrhizin, and DGL has removed it.

The tradeoff is that DGL also does not produce the cortisol-extending effects that make whole licorice interesting to anyone approaching it as a cortisol adaptogen. DGL is a different product for a different application.

Standardization labels that matter:

• "Glycyrrhizin" or "glycyrrhizinic acid" percentage tells you the active-risk compound content in a whole licorice product
• "DGL" or "deglycyrrhizinated" tells you the compound has been largely removed
• Unspecified "licorice root extract" with no glycyrrhizin content disclosed is a product you cannot evaluate for safety

An adaptogen brand can have credible-looking formulations and still fail to disclose glycyrrhizin content, which is the one number that matters most for licorice root safety. This is not a minor labeling gap.

Who should not take licorice root {#who-should-skip}

The list of hard contraindications for whole licorice root (glycyrrhizin-containing) is longer than for most other adaptogens. The following populations should not use glycyrrhizin-containing licorice products:

Absolute contraindications:

• Hypertension (any stage): glycyrrhizin will worsen blood pressure through mineralocorticoid mechanisms
• Chronic kidney disease: impaired potassium handling compounds hypokalemia risk
• Heart failure or cardiac disease: volume retention and electrolyte disturbance can precipitate decompensation
• Cardiac arrhythmia: hypokalemia is arrhythmogenic, and digoxin interaction risk is severe (see drug interactions below)
• Hypokalemia (low potassium): licorice accelerates potassium wasting
• Pregnancy: glycyrrhizin has been associated with adverse fetal outcomes; a 2002 Finnish cohort study (Strandberg et al., PMID 12193602) found that high prenatal licorice consumption was associated with shorter gestational length and developmental impacts on offspring cognition in follow-up assessments
• Breastfeeding: safety data are insufficient

Strong relative contraindications:

• Anyone taking antihypertensives (licorice counteracts them)
• Anyone taking potassium-depleting diuretics (additive hypokalemia)
• Anyone taking corticosteroids (potentiation of steroid effects)
• Anyone taking digoxin (hypokalemia from licorice increases digoxin toxicity risk, potentially fatal)
• Anyone taking MAOIs (licorice root has weak MAOI-like activity and can potentiate these drugs)
• Liver disease or cirrhosis

Dosing context and the WHO safety threshold {#dosing-context}

The World Health Organization's Joint Expert Committee on Food Additives (JECFA) has evaluated glycyrrhizin safety. In a 1999 evaluation, JECFA established a maximum acceptable daily intake (ADI) of 0.2 mg/kg body weight for glycyrrhizin, which corresponds to approximately 12–14 mg/day for a 70 kg adult. Longer-term risk assessments from European regulatory authorities have cited a practical safe threshold of roughly 100 mg/day glycyrrhizin for short-duration use in healthy adults, noting that chronic use at this level still carries risk.

To put this in context: a single stick of licorice candy can contain 50–100mg of glycyrrhizin. A standardized licorice root supplement capsule standardized to 18% glycyrrhizin at 500mg provides approximately 90mg per capsule. Two capsules daily from such a product would place most adults near or above the short-term safety threshold, and well above the WHO ADI.

The European Medicines Agency's (EMA) guidance on licorice root recommends limiting use of whole licorice root preparations to no more than 4 weeks without medical supervision and notes that products providing more than 100mg/day glycyrrhizin should include explicit hypertension warnings.

In clinical trials exploring therapeutic use of licorice in endocrine contexts, doses and duration have varied widely, and no standardized "safe dose for cortisol support" has been established in the peer-reviewed literature. Framing this as something you self-dose for stress management runs against the entire risk profile.

Actionable takeaway: There is no established safe long-term dose of glycyrrhizin for stress-adaptogen use. The WHO and EMA thresholds are risk-minimization guidelines for general consumers, not endorsements for supplement use.

Side effects, case reports, and drug interactions {#side-effects-interactions}

Documented adverse effects and case reports

The adverse effect profile of chronic glycyrrhizin consumption is well-documented in the medical literature, with a pattern called pseudohyperaldosteronism: hypertension, hypokalemia, edema, and muscle weakness, arising without actual elevated aldosterone.

A 2012 review by Nazari et al. (PMID 22299818) synthesized case reports of licorice-induced pseudohyperaldosteronism and noted presentations including: severe hypertension (systolic >200 mmHg in several cases), serum potassium dropping to below 2.0 mEq/L (life-threatening hypokalemia), rhabdomyolysis (muscle breakdown), and cardiac arrest in at least one reported case. The exposures triggering these events included both licorice confections and herbal supplements, at doses that were within what many supplement users consider routine.

A case series published in the American Journal of Medicine documented multiple presentations of licorice-induced hypertension resolving fully after discontinuation, with blood pressure normalization typically within 4 weeks of stopping licorice, and potassium levels recovering with supplementation.

These are not rare idiosyncratic reactions in uniquely susceptible individuals. Pseudohyperaldosteronism from licorice is a predictable pharmacological consequence of 11β-HSD2 inhibition, and the risk scales with dose and duration.

Drug interactions (this is the most important section for this herb)

Per the NCCIH licorice fact sheet, the antihypertensive and diuretic interactions are the most clinically significant and are the basis for licorice root's designation as an herb that requires physician oversight before use in anyone on prescription medications.

Actionable takeaway: Licorice root has a more dangerous drug-interaction profile than any other common adaptogen. The digoxin interaction alone can be life-threatening through a predictable pharmacological chain, not through an unusual reaction. Anyone taking prescription medications should treat this herb as off-limits without explicit physician sign-off.

Pregnancy warning

Glycyrrhizin crosses the placenta. A Finnish birth cohort by Strandberg et al. (PMID 12193602), following 1,049 children, found that high prenatal licorice consumption (more than 500mg glycyrrhizin/week) was associated with shorter gestational age and, in follow-up cognitive assessments, higher rates of ADHD-like symptoms in offspring. The evidence is observational with confounders, but licorice root is contraindicated in pregnancy. DGL should also be discussed with an OB before use.

Product context and what to look for {#product-context}

Given the risk profile, product picks for whole licorice root require a different framing than for adaptogens with cleaner safety records. The appropriate framing is: which products are safer, and which products are appropriate for which applications.

Now Foods DGL Licorice is a deglycyrrhizinated product, meaning the glycyrrhizin has been removed. This is appropriate for GI support (peptic ulcer, GERD symptom relief). It is not appropriate for cortisol-extension purposes because the mechanism compound has been removed. For most readers, DGL is the correct licorice product.

Pure Encapsulations Licorice is a whole licorice root extract. Third-party tested for contaminants, manufactured to NSF or GMP standards. For readers who are working with a physician on adrenal insufficiency support, this is a higher-quality whole licorice product. The glycyrrhizin content should be confirmed with the manufacturer before use. Not for self-dosing.

Solaray Licorice Root is a whole root product. Glycyrrhizin content varies by batch and is not consistently disclosed on the label, which is a meaningful limitation for risk assessment. Anyone needing to track glycyrrhizin intake (which is anyone who takes this herb) should request lot-specific COAs from the manufacturer.

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Frequently asked questions {#faq}

Does licorice root actually raise cortisol?

Not exactly. Glycyrrhizin extends cortisol's active lifespan in tissues by blocking the enzyme that converts it to inactive cortisone. Serum cortisol levels can appear unchanged on standard blood tests while cortisol activity in peripheral tissues, particularly the kidneys, is significantly elevated. The distinction matters because it produces mineralocorticoid side effects (high blood pressure, potassium loss) without a detectable serum cortisol spike.

What is pseudohyperaldosteronism, and why does licorice cause it?

Pseudohyperaldosteronism is a syndrome where the body behaves as if aldosterone levels are high (causing sodium retention, potassium wasting, and hypertension) even though measured aldosterone is actually low or normal. Glycyrrhizin causes it by mimicking aldosterone's effects at kidney mineralocorticoid receptors, via the 11β-HSD2 inhibition mechanism. The "pseudo" prefix distinguishes it from actual hyperaldosteronism (a tumor or adrenal disorder), even though the clinical presentation is similar.

How much licorice is dangerous?

This varies by individual. The WHO practical threshold is approximately 100mg/day glycyrrhizin for short-term use in healthy adults with normal blood pressure and kidney function. People with hypertension, kidney disease, heart disease, or taking interacting medications face risk at much lower doses. Case reports of serious adverse events have involved licorice candy consumed at amounts equivalent to 100–400mg glycyrrhizin daily over weeks to months. There is no established safe chronic dose.

Is DGL safe for daily use?

DGL has a substantially safer profile than whole licorice because the glycyrrhizin has been removed. Gastrointestinal use of DGL at standard doses (typically 380mg chewable, 20 minutes before meals) has not been associated with blood pressure effects or significant drug interactions in clinical use. The evidence base for DGL's GI efficacy is moderate, based on older RCTs for peptic ulcer support. DGL is not appropriate for cortisol support because the mechanism compound is absent.

Can licorice root help with adrenal fatigue?

"Adrenal fatigue" is not a recognized medical diagnosis, and no RCT has demonstrated that licorice root treats the commonly described symptoms. The theoretical basis for using licorice in adrenal insufficiency contexts is mechanistically plausible, but it has not been tested in controlled trials in otherwise-healthy adults with burnout-type fatigue. The risk-benefit math is unfavorable for self-treating fatigue with a herb that can cause cardiac complications.

What should I take instead for stress and cortisol support?

Ashwagandha (KSM-66 or Sensoril) has the strongest RCT evidence for cortisol reduction in chronically stressed adults. Rhodiola rosea (SHR-5 extract) has good evidence for fatigue and stress-related performance decline. Both have better safety profiles than licorice root for the stress-adaptogen use case. For a broader comparison, the Complete Guide to Adaptogens covers the evidence hierarchy across the major adaptogens.

Conclusion: the bottom line on licorice root and cortisol {#conclusion}

Licorice root's cortisol effect is real: glycyrrhizin blocks the enzyme that inactivates cortisol in kidney tissue, and the downstream consequences are raised blood pressure, potassium depletion, and a drug-interaction profile that includes life-threatening interactions with digoxin and direct opposition of antihypertensives. The claim that this mechanism makes licorice a safe cortisol adaptogen for general stress management is not supported by controlled trials in healthy adults.

DGL is the right licorice product for GI support, with glycyrrhizin removed. Ashwagandha or rhodiola are the right options for stress-and-cortisol support, with better evidence and cleaner safety profiles.

Next steps:

• If you're interested in adaptogens for stress, start with the Complete Guide to Adaptogens to see the full evidence landscape
• If you're researching cortisol-specific adaptogens, Best Adaptogens for Cortisol: Ranked by Evidence covers the ranked options with honest evidence summaries
• If you're on any prescription medications and considering any adaptogen, Adaptogens and Medications: The Complete Interaction Reference is required reading before you start
• If you've read about adaptogens and side effects broadly, the Adaptogen Side Effects Master List collects reported adverse events across the full category

Related reading {#related-reading}

• Complete Guide to Adaptogens: What Works, What Doesn't, and How to Choose
• Best Adaptogens for Cortisol: Ranked by Evidence
• Adaptogens and Medications: The Complete Interaction Reference
• Adaptogen Side Effects: The Master List

This article is for informational purposes and not medical advice. Licorice root (whole, glycyrrhizin-containing) carries documented risks of severe hypertension, hypokalemia, pseudohyperaldosteronism, and life-threatening drug interactions with digoxin, antihypertensives, and potassium-depleting diuretics. Hard contraindications include hypertension, kidney disease, heart failure, cardiac arrhythmia, pregnancy, and concurrent use of any of the drug classes listed in this article. DGL licorice has glycyrrhizin removed and a substantially different safety profile, but is not appropriate for cortisol support. Consult a licensed physician before using any licorice root product, particularly if you take prescription medications or have any cardiovascular, renal, or metabolic condition.

As an Amazon Associate, I earn from qualifying purchases. Product recommendations are based on real reviews and independent research.

This article is for informational purposes and not medical advice. Herbal adaptogens, even traditional ones, can interact with thyroid medication, antidepressants, anticoagulants, immunosuppressants, blood-pressure drugs, and more. Consult a licensed physician before starting any adaptogen, particularly if you are pregnant, nursing, taking prescription medications, or managing a chronic condition.