Liquorice Extract
Also known as: Licorice extract, Licorice root extract, Glycyrrhizic acid, Glycyrrhiza glabra
Overview
Licorice extract, primarily derived from the root of Glycyrrhiza glabra, is a herbal supplement rich in bioactive compounds like glycyrrhizic acid and flavonoids. Traditionally used for liver support, anti-inflammatory effects, and digestive health, modern research explores its potential anti-fibrotic, anti-obesity, and blood pressure-modulating properties. The research maturity is moderate, with several systematic reviews and meta-analyses supporting its effects on liver fibrosis, metabolic parameters, and blood pressure. Evidence quality is generally good, including multiple randomized controlled trials. It is available in various forms, often standardized for glycyrrhizic acid content.
Benefits
Licorice extract offers several evidence-based benefits. A meta-analysis of four RCTs demonstrated that glycyrrhizic acid significantly reduced markers of liver fibrosis, including TGF-β1 mRNA expression and related proteins, with a notable reduction in alanine aminotransferase (ALT) by -18.12 U/L (95% CI -30.02 to -6.22, p=0.00). This indicates a strong anti-fibrotic effect. For metabolic health, a 2018 meta-analysis showed that licorice consumption led to statistically significant reductions in body weight and BMI in overweight or obese patients, suggesting potential anti-obesity benefits. However, it's crucial to note that a 2024 systematic review and meta-analysis reported that licorice functional components can increase blood pressure, highlighting a dose-dependent hypertensive effect. While benefits for liver fibrosis and metabolic parameters are clinically relevant and typically manifest over weeks to months, the blood pressure elevation requires significant caution.
How it works
Glycyrrhizic acid, a primary active compound in licorice extract, exerts its anti-fibrotic effects by inhibiting TGF-β1 and Smad signaling pathways, which are crucial in the development of liver fibrosis. The mechanism behind its blood pressure modulation involves the inhibition of 11β-hydroxysteroid dehydrogenase type 2. This inhibition leads to increased cortisol activity at mineralocorticoid receptors, resulting in sodium retention and subsequent hypertension. Flavonoids and other constituents present in licorice may contribute to its metabolic benefits by modulating lipid metabolism and adipogenesis, thereby aiding in weight reduction. The bioavailability of glycyrrhizic acid is influenced by its intestinal metabolism to glycyrrhetinic acid, which is considered the more active form.
Side effects
While generally safe at low to moderate doses, licorice extract can cause significant side effects, primarily due to its mineralocorticoid effects. The most common adverse effects, occurring in over 5% of users, include hypertension (high blood pressure), hypokalemia (low potassium levels), and edema (fluid retention). Less common side effects (1-5%) may include headache and gastrointestinal discomfort. Rare but severe adverse events (<1%) can involve severe electrolyte imbalances and cardiac arrhythmias, particularly in susceptible individuals. Licorice extract has important drug interactions; caution is advised when co-administered with antihypertensives, diuretics, corticosteroids, and any medications affecting potassium levels. It is contraindicated in individuals with uncontrolled hypertension, heart failure, kidney disease, and during pregnancy. Special populations, such as the elderly and those with pre-existing cardiovascular risks, require careful monitoring due to increased susceptibility to adverse effects.
Dosage
Effective doses of licorice extract vary depending on the intended use and the concentration of active compounds. For liver fibrosis, studies have utilized glycyrrhizic acid doses ranging from 50-150 mg per day. For metabolic benefits, licorice extract doses providing 100-200 mg per day of active components have shown positive results. However, due to the risk of hypertension, the maximum safe dose for chronic intake should not exceed 100 mg of glycyrrhizic acid per day. Dosing timing is generally flexible, but consistent daily intake is typical in clinical trials. Standardized extracts with a defined glycyrrhizic acid content are preferred to ensure consistent dosing. Absorption can be enhanced when taken with food, and intestinal microbiota play a role in converting glycyrrhizic acid into its active metabolites.
FAQs
Is licorice extract safe for long-term use?
Long-term use at high doses is not recommended due to the risk of hypertension and electrolyte disturbances. Short-term use under medical supervision is generally considered safer.
Can licorice extract lower blood pressure?
No, licorice extract tends to increase blood pressure due to its mineralocorticoid effects and should be avoided by individuals with hypertension or those at risk.
How soon do benefits appear?
Benefits for liver health and metabolic parameters typically become noticeable after several weeks of consistent daily use, as observed in clinical studies.
Is it effective for weight loss?
Licorice extract may contribute to modest reductions in body weight and BMI, but it should be used as part of a comprehensive approach that includes lifestyle changes.
Research Sources
- https://www.scielo.br/j/cta/a/8BkTCwd3yPd43tqdpQ3f9NQ/ – This meta-analysis of four RCTs investigated the effects of glycyrrhizic acid on liver fibrosis markers. It found significant reductions in TGF-β1, Smad mRNAs, and ALT levels, indicating its efficacy in mitigating liver injury and fibrosis. The study highlights the potential of glycyrrhizic acid as an anti-fibrotic agent.
- https://pubmed.ncbi.nlm.nih.gov/39519602/ – This systematic review and meta-analysis explored the impact of licorice functional components on blood pressure. It concluded that licorice intake can increase blood pressure in a dose-dependent manner, primarily through mineralocorticoid-like activity, emphasizing the need for caution in susceptible populations.
- https://pubmed.ncbi.nlm.nih.gov/29433679/ – This systematic review and meta-analysis assessed the metabolic effects of licorice in overweight or obese adults. It reported statistically significant reductions in body weight and BMI, suggesting a potential role for licorice in managing obesity, though with moderate heterogeneity in findings.
