Gan Cao

Glycyrrhiza uralensis

Physical Characteristics

Glycyrrhiza uralensis is a PERENNIAL growing to 0.6 m (2ft) by 0.4 m (1ft 4in). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from June to August, and the seeds ripen from July to October. The species is hermaphrodite (has both male and female organs). It can fix Nitrogen. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

E. Asia - China, Japan, Siberia.

Habitats

Cultivated Beds;

Edible Uses

Edible Parts: Root Edible Uses: Sweetener The fibrous root is used as a sweetener for foods[183]. It is boiled in water to extract the sugars etc and used as a liquorice substitute in sweets, medicines, drinks etc[74, 174, 177]. The root contains glycyrrhizin, which is 50 times sweeter than sugar[218].

Medicinal Uses

Antiphlogistic Antispasmodic Antitussive Cholagogue Emollient Expectorant Gan Cao is commonly used in Chinese herbalism, where it is considered to be one of the 50 fundamental herbs[218]. It is considered to be second in importance only to Ginseng (Panax spp)[218]. Used in excess, however, it can cause cardiac dysfunction and severe hypertension[218]. The root is a sweet tonic herb that stimulates the corticosteroidal hormones, neutralizes toxins and balances blood sugar levels[238]. It is also antibacterial, anti-inflammatory, antiphlogistic, antispasmodic, antitussive, cholagogue, demulcent, emollient, expectorant and laxative[61, 176, 218, 238]. It is used internally in the treatment of Addison's disease, asthma, coughs and peptic ulcers[238]. Externally, it is used to treat acne, boils and sore throats[238]. It is included in almost all Chinese herbal formulae, where it is said to harmonize and direct the effects of the various ingredients[238]. It precipitates many compounds and is therefore considered to be unsuitable for use with some herbs such as Daphne genkwa, Euphorbia pekinensis and Corydalis solida[238]. It increases the toxicity of some compounds such as ephedrine, salicylates, adrenaline and cortisone[238]. It should not be prescribed for pregnant women or for people with high blood pressure, kidney disease or anyone taking digoxin-based medications[238]. Excessive doses cause water retention and high blood pressure[238]. It can cause impotence in some people[238]. The roots are harvested in early autumn, preferably from plants 3- 4 years old, and is dried for later use[238]. The flowers are alterative and expectorant[218].

Known Hazards

None known