Licorice Root for HSV: Can This Traditional Herb Help Cold Sores and Herpes?

What Is Licorice Root?

Licorice root has traditionally been used to support a variety of health concerns, including:

• Digestive irritation
• Respiratory symptoms such as cough
• Inflammatory conditions
• Immune function
• Recovery during periods of physical or emotional stress¹

The herb contains hundreds of naturally occurring compounds, but glycyrrhizin is considered one of its best-studied active constituents.¹

Because glycyrrhizin can increase blood pressure in some individuals when taken in high amounts or for prolonged periods, deglycyrrhizinated licorice (DGL) is often used in digestive health supplements. DGL has most of the glycyrrhizin removed, making it a different preparation with different clinical uses.⁴

Can Licorice Root Help with HSV?

Research suggests licorice root may have several properties that could be beneficial for HSV, although **most of the evidence comes from laboratory and animal studies rather than large human clinical trials.**¹,²

May Have Direct Antiviral Effects

Laboratory studies have found that glycyrrhizin may interfere with several stages of the HSV life cycle. Researchers have observed that it may help reduce viral replication, decrease the virus’s ability to infect healthy cells, and limit viral activity under experimental conditions.²

While these findings are encouraging, they do not necessarily mean licorice root alone can prevent or treat HSV outbreaks in people.

May Support a Healthy Immune Response

Licorice root also appears to influence immune function by helping regulate inflammatory pathways and supporting the activity of several immune cells.³

Because HSV remains dormant in nerve cells and can reactivate when immune defenses are compromised, supporting overall immune health may play an important role in reducing recurrent outbreaks. However, licorice root should be viewed as one piece of a comprehensive management plan rather than a standalone treatment.

May Help the Body Respond to Stress

Many people notice HSV outbreaks occur during periods of illness, poor sleep, or psychological stress.

Licorice root has traditionally been used to support the body’s response to stress, and some research suggests it may influence the body’s stress-response systems.³ Since stress is a well-recognized trigger for HSV reactivation, lifestyle habits that reduce chronic stress remain an important part of outbreak prevention.

Is Licorice Root Safe?

Licorice root has a long history of traditional use and is generally considered safe **when used appropriately and under the guidance of a qualified healthcare practitioner.**⁴

However, glycyrrhizin-containing licorice can cause side effects when taken in high doses or over long periods, including:

• Elevated blood pressure
• Low potassium levels (hypokalemia)
• Fluid retention
• Heart rhythm disturbances in susceptible individuals⁴

Licorice root may not be appropriate if you:

• Have high blood pressure
• Have kidney or heart disease
• Have low potassium levels
• Take diuretics, corticosteroids, digoxin, or certain blood pressure medications⁴

Always speak with your healthcare provider before starting licorice root, especially if you have underlying medical conditions or take prescription medications.

The Bottom Line

Licorice root is one of the most extensively studied medicinal herbs, and its active compound, glycyrrhizin, has demonstrated antiviral activity against HSV in laboratory research. It may also help support healthy immune function and inflammation, which are important factors in HSV management.¹–³

While the early evidence is promising, human clinical trials remain limited. Licorice root should be considered a complementary strategy alongside evidence-based treatments, healthy lifestyle habits, and guidance from a qualified healthcare practitioner.

References

1. Pastorino G, Cornara L, Soares S, Rodrigues F, Oliveira MBPP. Liquorice (Glycyrrhiza glabra): A phytochemical and pharmacological review. Phytother Res. 2018;32(12):2323-2339.
2. Wang L, Yang R, Yuan B, Liu Y, Liu C. The antiviral and antimicrobial activities of licorice, a widely used Chinese herb. Acta Pharm Sin B. 2015;5(4):310-315.
3. Ram A, Mabalirajan U. Glycyrrhizin: A promising anti-inflammatory, immunomodulatory and antiviral agent. Pharmacol Res. 2021;170:105718.
4. Ulbricht C, Isaac R, Milkin T, et al. An evidence-based systematic review of licorice by the Natural Standard Research Collaboration. J Diet Suppl. 2005;2(4):1-114.