Quick Summary

Licorice (Glycyrrhiza glabra) is a medicinal plant traditionally used for various health purposes including oral mucositis, gastrointestinal disorders, and skin conditions. Recent research focuses on its potential to manage chemotherapy- and radiotherapy-induced oral mucositis and to promote healing of burn wounds. Key compounds such as glycyrrhizic acid and flavonoids are believed to contribute to its pharmacological effects. Existing evidence suggests possible anti-inflammatory and healing benefits, though clinical study quality and consistency vary. Notably, licorice’s glycyrrhizic acid content may affect blood pressure, requiring cautious use.

What Is It?

Licorice is a perennial herb native to parts of Europe and Asia, commonly harvested for its sweet-flavored root. The root contains several bioactive constituents, most notably glycyrrhizic acid and flavonoids, which have been studied for medicinal properties. Licorice extracts are available in various forms such as topical gels, hydrogels, and systemic preparations.

Traditional Uses

Traditionally, licorice has been used to soothe gastrointestinal complaints, treat oral and skin inflammation, and support wound healing. Its demulcent and anti-inflammatory properties made it popular in folk medicine for managing mucosal irritations and burns.

Active Compounds

  • Glycyrrhizic acid (GA): Main compound linked to anti-inflammatory and modulating effects but also responsible for blood pressure changes.
  • Flavonoids: Believed to contribute antioxidant and anti-inflammatory activities with less impact on blood pressure.

Potential Benefits with Evidence Levels

  • Reduction in chemotherapy- and radiotherapy-induced oral mucositis in head and neck cancer patients (Low to moderate evidence): A systematic review of nine studies suggests licorice may reduce the severity and duration of mucositis. Variations in topical versus systemic use may influence effectiveness. (PMID: 41640660)
  • Promotion of wound healing in second-degree burns (Preclinical animal study): In murine models, 5% licorice extract hydrogels enhanced wound closure and barrier restoration with favorable safety profiles. (PMID: 41149438)
  • Management of radiotherapy-induced oral mucositis (Preliminary clinical evidence): Herbal antioxidant topical gels containing licorice exhibited protective effects and accelerated recovery in a small randomized trial without reported adverse effects. (PMID: 41907896)
  • Pain reduction in orofacial conditions (Moderate evidence): A systematic review and meta-analysis indicated that licorice among other herbal extracts may have analgesic effects on orofacial pain, though study heterogeneity limits firm conclusions. (PMID: 39609444)

Side Effects

  • Hypertension and increased blood pressure mainly related to glycyrrhizic acid intake (PMID: 39519602).
  • Potential for electrolyte imbalance and cardiovascular effects due to glycyrrhizic acid.
  • Mild side effects with topical or systemic use have been reported, though serious adverse events appear rare or unreported specifically for licorice.

Drug Interactions

No detailed clinical evidence specifically addresses drug interactions with licorice. However, based on its pharmacology, preparations high in glycyrrhizic acid may interact with antihypertensive agents and drugs altering potassium levels. Further clinical research is needed to clarify these interactions.

Who Should Avoid It

Licorice use may be contraindicated or should be approached with caution in individuals with hypertension, cardiovascular disease, or those predisposed to electrolyte imbalances due to its potential to raise blood pressure. Additionally, pregnant or breastfeeding women are advised to avoid licorice due to lack of safety data in these populations.

Evidence Limitations

  • Overall clinical studies are limited by small sample sizes, heterogeneous designs, and low methodological quality.
  • Many positive results originate from small randomized controlled trials or preclinical animal models, restricting generalizability.
  • Lack of standardization in licorice preparations and dosing schemes complicates comparisons across studies.
  • Safety data is mainly observational with insufficient controlled trials reporting adverse events or drug interactions.
  • Long-term safety and appropriate dosing remain poorly defined.
  • No high-quality systematic reviews or meta-analyses are specific to licorice alone for most indications.

References

Last Reviewed

June 2025

Disclaimer

This information is intended for educational purposes only and does not constitute medical advice. Licorice and its preparations may have side effects and interact with medications. Consult a qualified healthcare provider before use, especially if you have underlying health conditions or are pregnant or breastfeeding. More high-quality research is needed to fully establish licorice’s safety and efficacy.