Liquorice or licorice is the root of Glycyrrhiza glabra from which a somewhat sweet flavor can be extracted. The liquorice plant is a legume that is native to southern Europe and parts of Asia. It is not botanically related to anise, star anise, or fennel, which are sources of similar flavouring compounds.
Liquorice flavour is found in a wide variety of liquorice candies or sweets. In most of these candies the taste is reinforced by aniseed oil, and the actual content of liquorice is very low. Liquorice confections are primarily purchased by consumers in the European Union.
In the Netherlands, where liquorice candy ("drop") is one of the most popular forms of sweet, only a few of the many forms that are sold contain aniseed, although mixing it with mint, menthol or with laurel is quite popular. Mixing it with ammonium chloride ('salmiak') is also popular. The most popular liquorice, known in the Netherlands as zoute drop (salty liquorice) actually contains very little salt, i.e. sodium; the salty taste is probably due to ammonium chloride, and the blood pressure raising effect is due to glycyrrhizin, see below. Strong, salty candies are popular in Scandinavia.
Pontefract in Yorkshire was the first place where liquorice mixed with sugar began to be used as a sweet in the same way it is in the modern day. Pontefract cakes were originally made there. In County Durham, Yorkshire and Lancashire it is colloquially known as Spanish, supposedly because Spanish monks grew liquorice root at Rievaulx Abbey near Thirsk.
Liquorice is popular in Italy (particularly in the South) and Spain in its natural form. The root of the plant is simply dug up, washed and chewed as a mouth freshener. Throughout Italy unsweetened liquorice is consumed in the form of small black pieces made only from 100% pure liquorice extract; the taste is bitter and intense. In Calabria a popular liqueur is made from pure liquorice extract. Liquorice is also very popular in Syria where it is sold as a drink. Dried liquorice root can be chewed as a sweet. Black liquorice contains approximately 100 calories per ounce (15 kJ/g).
The compound glycyrrhizin (or glycyrrhizic acid), found in liquorice, has been proposed as being useful for liver protection in tuberculosis therapy, however evidence does not support this use which may in fact be harmful. Glycyrrhizin has also demonstrated antiviral, antimicrobial, anti-inflammatory, hepatoprotective and blood-pressure increasing effects in vitro and in vivo, as is supported by the finding that intravenous glycyrrhizin (as if it is given orally very little of the original drug makes it into circulation) slows the progression of viral and autoimmune hepatitis. Liquorice has also demonstrated promising activity in one clinical trial, when applied topically, against atopic dermatitis. Additionally liquorice has also proven itself effective in treating hyperlipidaemia (a high amount of fats in the blood). Liquorice has also demonstrated efficacy in treating inflammation-induced skin hyperpigmentation. Liquorice may also be useful in preventing neurodegenerative disorders and cavities. Anti-ulcer, laxative, anti-diabetic, anti-inflammatory, immunomodulatory, antitumour and expectorant properties of liquorice have also been noted.
In traditional Chinese medicine, liquorice is commonly used in herbal formula to "harmonize" the other ingredients in the formula and to carry the formula to the twelve "regular meridians".
Liquorice may be useful in conventional and naturopathic medicine for both mouth ulcers and peptic ulcers.