Clove is widely cultivated in Indonesia, Sri-Lanka, Madagascar, Tanzania, and Brazil. It is used in limited amounts in food products as a fragrant, flavoring agent, and antiseptic. Clinical trials assessing monotherapy of clove are limited, although the expert panel German Commission E has approved the use of clove as a topical antiseptic and anesthetic. Other uses for clove, such as premature ejaculation, dry socket, and fever reduction, lack reliable human clinical evidence. Clove is sometimes added to tobacco in cigarettes, and clove cigarettes ("kreteks") typically contain 60% tobacco and 40% ground cloves. Eugenol, a constituent of clove, has been used for analgesic, local anesthetic, anti-inflammatory, and antibacterial effects. It is used in the form of a paste or mixture as dental cement, filler, and restorative material. Plant oils, including clove, may be used in livestock to inhibit microbial fermentation in waste products. Clove oil may be found in high concentration licorice (glycyrrhizin) products to prevent gel formation in an aqueous solution.