Liquorice, or licorice, (/ˈlɪkrɪʃ, ˈlɪkər-, -ɪs/ lik-(ə-)rishlik-(ə-)ris) is the root of Glycyrrhiza glabra from which a sweet flavour can be extracted. The liquorice plant is a herbaceous perennial legume native to southern Europe and parts of Asia, such as India. It is not botanically related to anisestar anise, or fennel, which are sources of similar flavouring compounds.

Most liquorice is used as a flavouring agent for tobacco, particularly US blend cigarettes, to which liquorice lends a natural sweetness and a distinctive flavour and makes it easier to inhale the smoke by creating bronchodilators, which open up the lungs. Liquorice flavours are also used as candies or sweeteners, particularly in some European and Middle Eastern countries. Liquorice extracts have a number of medical uses, and they are also used in herbal and folk medications. Excessive consumption of liquorice (more than 2 mg/kg/day of pure glycyrrhizinic acid, a liquorice component) may result in adverse effects, and overconsumption should be suspected clinically in patients presenting with otherwise unexplained hypokalemia and muscle weakness.

The word liquorice is derived (via the Old French licoresse) from the Greek γλυκύρριζα (glukurrhiza), meaning “sweet root”, from γλυκύς (glukus), “sweet” + ῥίζα (rhiza), “root”, the name provided by Dioscorides. It is usually spelled liquorice in British usage, but licorice in the United States and Canada.

The scent of liquorice root comes from a complex and variable combination of compounds, of which anethole is up to 3% of total volatiles. Much of the sweetness in liquorice comes from glycyrrhizin, which has a sweet taste, 30–50 times the sweetness of sugar. The sweetness is very different from sugar, being less instant, tart, and lasting longer.

The isoflavene glabrene and the isoflavane glabridin, found in the roots of liquorice, are phytoestrogens.

Liquorice, which grows best in well-drained soils in deep valleys with full sun, is harvested in the autumn two to three years after planting. Countries producing liquorice include India, Iran, Italy, Afghanistan, the People’s Republic of China, Pakistan, Iraq, Azerbaijan, Uzbekistan, Turkmenistan,Turkey, and England.

The world’s leading manufacturer of liquorice products is M&F Worldwide, which manufactures more than 70% of the worldwide liquorice flavours sold to end users.

Most liquorice is used as a flavouring agent for tobacco. For example, M&F Worldwide reported in 2011 that about 63% of its liquorice product sales are to the worldwide tobacco industry for use as tobacco flavour enhancing and moistening agents in the manufacture of American blend cigarettes, moist snuff, chewing tobacco, and pipe tobacco.American blend cigarettes made up a larger portion of worldwide tobacco consumption in earlier years, and the percentage of liquorice products used by the tobacco industry was higher in the past. M&F Worldwide sold approximately 73% of its liquorice products to the tobacco industry in 2005. A consultant to M&F Worldwide’s predecessor company stated in 1975 that it was believed that well over 90% of the total production of liquorice extract and its derivatives found its way into tobacco products.

Liquorice provides tobacco products with a natural sweetness and a distinctive flavour that blends readily with the natural and imitation flavouring components employed in the tobacco industry. It represses harshness and is not detectable as liquorice by the consumer. Tobacco flavourings such as liquorice also make it easier to inhale the smoke by creating bronchodilators, which open up the lungs. Chewing tobacco requires substantially higher levels of liquorice extract as emphasis on the sweet flavour appears highly desirable.