Glycyrrhiza glabra (Liquorice) is perennial herb native to various regions in the world including the Mediterranean, Russia, and the Middle East. It is now cultivated in various habitats around the world. Due to its sweet taste, Liquorice is commonly used as a flavouring agent in food and herbal medicines.
Historical uses:
Liquorice has a long history of use and is referred to as the ‘Father of Herbal Medicine’. The ancient Egyptians consumed it as a sweet drink, and it was later imported to China where it is known as ‘Gan Cao’ meaning ‘sweet grass.’ The use of Liquorice was also documented by the Assyrians, Greeks and Romans and was used by soldiers and travellers to suppress thirst on long marches across battlefields and in the desert as well as during fasting periods such as Ramadan. In herbal and folk medicine, Liquorice was traditionally used for treatment for diseases of the digestive and respiratory system. It has also been traditionally viewed as an adrenal tonic in herbal medicine due to its ability to slow the breakdown of the stress hormone cortisol.
Fun Fact: The Latin name Glycyrrhiza comes from the Greek word meaning “sweet root,” which is descriptive of the very sweet flavour of this herb, known to be 50 times sweeter than sucrose!
Part Used:
- Root
Major Chemical Constituents:
Gychyrrhizin, saponins, flavonoids
Therapeutic actions:
Anti-inflammatory, Anti-ulcer, Expectorant
Key benefits based on traditional and clinical use:
- Soothes and heals the mucous membranes of the GIT.
- Reduces symptoms of indigestion (functional dyspepsia) such as bloating, fullness and pain.
- Expectorant for coughs and clearing of phlegm.
- Supports the adrenal glands.
- Topically to relieve symptoms of eczema
Evidence for clinical use:
1. Healing of peptic ulcers induced by H. Pylori infection
In a double-blind trial involving 40 patients with peptic ulcer, Liquorice was found to be an effective substitute for bismuth sub nitrate alongside triple antibiotic therapy, demonstrating enhanced healing of the peptic ulcers with no adverse effects noted.
2. Decrease symptoms of functional dyspepsia (indigestion)
A 2011 randomized double-blind, placebo-controlled, clinical trial found that GutGard® a standardised extract of Glycyrrhiza glabra (deglycyrrhized liquorice) root taken at 75mg twice daily for 30 days showed significantly improved quality of life and decrease in symptoms of functional dyspepsia such as upper abdominal fullness and epigastric pain.
3. Topically for relief of symptoms of atopic skin conditions
A small 2003 randomised controlled trial of 30 subjects found that a topical application of two percent Liquorice topical gel was effective in reducing redness, swelling and itching associated with atopic dermatitis over a 2-week period. A subsequent systematic review of randomised controlled trials conducted in 2017 found that Liquorice gel was superior to placebo for the management of the symptoms of atopic eczema.
Cautions/Contraindications:
Due to the glycyrrhizin content in Liquorice root, large doses over an extended period may cause depletion of potassium levels and fluid retention leading to increased blood pressure. Caution is advised in people with a history of high blood pressure, heart failure, kidney, or liver disease. Not recommended during pregnancy or lactation. Avoid taking with blood pressure medications and potassium depleting diuretics.
Note: Liquorice processed to remove glycyrrhizin, results in DGL (deglycyrrhizinated Liquorice) DGL is commonly found in gut supplements to treat gastric ulcers and does not have the same effect on blood pressure. Always consult your healthcare professional to determine if supplementation is suitable for you.
