How does licorice root affect cortisol levels in the body?

Licorice root impacts cortisol by inhibiting the enzyme 11-beta-hydroxysteroid dehydrogenase type 2. This enzyme typically converts active cortisol into inactive cortisone. By blocking this conversion, glycyrrhizin extends the half-life of circulating cortisol, enhancing its anti-inflammatory and adrenal-supportive effects (Evidence Level: B). This mechanism makes licorice useful for adrenal fatigue but explains why prolonged use can lead to cortisol-related side effects like fluid retention and hypertension.

Can I take licorice root with high blood pressure medication?

You should avoid taking licorice root if you are on high blood pressure medication. Glycyrrhizin causes sodium retention and potassium excretion, which directly counteracts the effects of antihypertensive drugs like diuretics and ACE inhibitors (Evidence Level: B). This interaction can lead to dangerously elevated blood pressure and hypokalemia. Patients on hypertension medication should consult a physician before using any licorice supplements.

What is the standard dosage for licorice root?

For adults, the standard dosage for a standardized licorice extract is 200–600 mg daily (Evidence Level: B). For digestive issues without the risk of raising blood pressure, Deglycyrrhizinated Licorice (DGL) is preferred, typically dosed at 380–760 mg taken 20 minutes before meals. Whole root usage should generally be limited to 4–6 weeks to avoid mineralocorticoid side effects unless monitored by a healthcare provider.

Is licorice root safe to take during pregnancy?

Licorice root is considered unsafe during pregnancy and should be avoided (Evidence Level: B). Studies suggest that consuming glycyrrhizin during pregnancy is associated with an increased risk of preterm birth and may affect fetal development. It can also raise maternal blood pressure and cause edema. Pregnant women are advised to avoid medicinal doses of licorice and limit consumption of licorice-containing foods.

What is the difference between licorice root and DGL supplements?

The primary difference lies in the glycyrrhizin content. Standard licorice root contains glycyrrhizin, which is responsible for adrenal and respiratory benefits but also causes high blood pressure and potassium depletion. DGL (deglycyrrhizinated licorice) has had this compound removed, making it safe for long-term use and suitable for those with hypertension. Consequently, DGL is preferred for treating acid reflux and ulcers, while whole licorice is reserved for adrenal support (Evidence Level: B).

Licorice Root (Glycyrrhiza glabra)

What is a herb–drug interaction?

A herb–drug interaction happens when a plant or supplement changes how a medication works in your body — making it stronger, weaker, or more likely to cause harm. Herbs contain active compounds that can speed up or slow down the enzymes and transporters your body uses to process drugs.

Why it matters

St. John's Wort can make birth control, antidepressants, and blood thinners less effective.

Garlic can increase bleeding risk with warfarin and other blood thinners (also ginkgo, ginger, and turmeric).

Kava can amplify sedation when taken with anxiety or sleep medications (also valerian).

The risk is highest for older adults, anyone taking several medications, and people with chronic conditions.

Always tell your doctor and pharmacist about every herb and supplement you take — and check below before combining.

Known Drug Interactions (6)

4 Severe2 Moderate

Drug	Severity	Description
Spironolactone	Severe	Licorice may counteract the effects of spironolactone, reducing its blood pressure-lowering and potassium-sparing effects.
Antihypertensive medications (general)	Moderate	Licorice root can cause sodium retention and potassium loss, raising blood pressure and counteracting antihypertensive medication effects.
Digoxin	Severe	Licorice-induced hypokalemia can increase sensitivity to digoxin toxicity, potentially causing dangerous cardiac arrhythmias.
Hydrochlorothiazide (HCTZ)	Severe	Licorice may worsen potassium loss caused by thiazide diuretics, potentially leading to dangerous hypokalemia, cardiac arrhythmias, and muscle weakness.
Furosemide (Lasix)	Severe	Licorice combined with loop diuretics can cause severe potassium depletion and dangerous hypokalemia.

This list reflects a curated subset of documented interactions and is not exhaustive. The absence of a drug here is not proof that it is safe to combine. Always confirm with a pharmacist or healthcare provider.

PubMed-compiled information sheet

This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.

Compiled from 28 PubMed articles · model: gemma4:31b

Summary

Licorice Root (Glycyrrhiza glabra) is a perennial herb used since ancient times for its broad range of pharmacological activities, including anti-inflammatory and antiviral effects [PMID:30117204, PMID:34961221].

Background

Glycyrrhiza glabra Linn. is a small perennial undershrub belonging to the Fabaceae family, native to Mediterranean countries, Asia, Turkey, Iraq, Iran, and southern Russia [PMID:30117204, PMID:30049263, PMID:34739794].

Traditional uses

Traditionally used across Ancient Egyptian, Roman, Greek, and Chinese medicine to treat respiratory disorders, throat infections, tuberculosis, stomach ulcers, hepatitis C, skin diseases, jaundice, epilepsy, fever, and sexual debility [PMID:34961221, PMID:37043593, PMID:32106571].

Active compounds

Key bioactive constituents include glycyrrhizin (glycyrrhizic acid), 18β-glycyrrhetinic acid, glabridin, isoliquiritigenin, licochalcones, isoflavones, and various triterpene saponins [PMID:30117204, PMID:37288311, PMID:18703197, PMID:33401375].

Mechanism of action

Licorice compounds target multiple signaling pathways, including NF-κB, TGF-β1, JNK, MAPK, p53, STAT3, and HMGB1 to alleviate kidney injury [PMID:41357892]. In cancer, constituents may inhibit B-cell lymphoma 2, cyclin-dependent kinase 2, PI3K, and mTOR [PMID:36474507].

Clinical evidence

Evidence CAtherosclerosis

Demonstrates anti-inflammatory, anti-cytokine, antioxidant, anti-atherogenic, and anti-platelet actions [PMID:35897875]

Evidence CMetabolic Syndrome

Affects blood glucose and lipid profiles, though it can increase blood pressure [PMID:34981491]

Evidence DObesity (Animal Model)

Extract significantly reduced body weight increases and provided hepatoprotective effects in obese rats [PMID:39404468]

Evidence DCOVID-19 (In vitro/Pre-clinical)

Triterpenoids such as licorice-saponin A3 and glycyrrhetinic acid potently inhibit SARS-CoV-2 infection [PMID:35116174]

Safety & adverse effects

High doses can cause serious adverse events, including hypertension, hypokalemia, and syndrome of apparent mineralocorticoid excess (pseudohyperaldosteronism) [PMID:37043593, PMID:17320224, PMID:39331666]. G. glabra and glycyrrhizin salts are described as moderately toxic [PMID:28833680].

Pregnancy & lactation

Licorice is a purported galactogogue, but no scientifically valid clinical trials support this; it may actually reduce serum prolactin and decrease milk production in early lactation [PMID:30000900]. Glycyrrhizin has been detected in breastmilk [PMID:30000900].

Evidence summary

The evidence consists primarily of reviews and pre-clinical/animal studies (Levels C and D), indicating strong pharmacological potential but highlighting significant safety risks associated with high-dose consumption.

PubMed sources

1.PMID: 30117204 (2018) — Liquorice (Glycyrrhiza glabra): A phytochemical and pharmacological review. · Phytotherapy research : PTR
2.PMID: 28833680 (2017) — Toxicological Effects of Glycyrrhiza glabra (Licorice): A Review. · Phytotherapy research : PTR
3.PMID: 34961221 (2021) — Glycyrrhiza glabra (Licorice): A Comprehensive Review on Its Phytochemistry, Biological Activities, Clinical Evidence and Toxicology. · Plants (Basel, Switzerland)
4.PMID: 37043593 (2012) — Review of pharmacological effects of Glycyrrhiza sp. and its bioactive compounds. · Phytotherapy research : PTR
5.PMID: 32106571 (2020) — Traditional Uses, Bioactive Chemical Constituents, and Pharmacological and Toxicological Activities of Glycyrrhiza glabra L. (Fabaceae).

Licorice Root

Sources & Citations

Thyme

Marshmallow Root

Libyan Thyme

⚠️ Not Recommended During Pregnancy or Nursing

6 Known Drug Interactions — Some May Be Serious

Contraindications

Possible Side Effects

What is a herb–drug interaction?

Known Drug Interactions (6)

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Pregnancy & lactation

Evidence summary

PubMed sources

Government sources

Licorice Root

Sources & Citations

Related Herbs

Thyme

Marshmallow Root

Libyan Thyme

⚠️ Not Recommended During Pregnancy or Nursing

6 Known Drug Interactions — Some May Be Serious

Contraindications

Possible Side Effects

What is a herb–drug interaction?

Known Drug Interactions (6)

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Pregnancy & lactation

Evidence summary

PubMed sources

Government sources