Castoreum

Castoreum is the name given to the exudate from the castor sacs of the mature North American Beaver Castor canadensis and the European Beaver, Castor fiber. Within the zoological realm, castoreum is the yellowish secretion of the castor sac in combination with the beaver's urine, used during scent marking of territory. Both male and female beavers possess a pair of castor sacs and a pair of anal glands located in two cavities under the skin between the pelvis and the base of the tail. The castor sacs are not true glands (endocrine or exocrine) on a cellular level, hence references to these structures as preputial glands or castor glands are misnomers.

Today, it is used in trapping, as a tincture in some perfumes, or touted as an aphrodisiac.

Castoreum in Perfume
In perfume-making, the term castoreum is more liberally applied to denote the resinoid extract resulting from the dried and alcohol tinctured beaver castor (www.hyraceum.com). The dried beaver castor sacs are generally aged for two or more years to mellow and for their raw harshness to dissipate. In perfumery, castoreum has largely been used as an animalic note suggesting leather, compounded with other ingredients including top, middle, and base notes as a composition. Some classic perfumes incorporating castor are Emeraude, Coty Chanel Cuir de Russie, Magie Noire, Lancôme Caractère, Hechter Madame, Carven, Givenchy III, Shalimar, and many "leather" themed compositions. Twenty four compounds known to be constituents of beaver castoreum were individually screened for pheremonal activity. These are the phenols 4-ethylphenol and 1,2-dihydroxybenzene and the ketones acetophenone and 3-hydroxyacetophenone. Five additional compounds noted are 4-methyl-1,2-dihydroxybenzene, 4-methoxyacetophenone, 5-methoxysalicylic acid, salicylaldehyde, and 3-hydroxybenzoic acid.

Medicinal Use of Castoreum
Although modern medical use of castoreum is rare, the dried pair of scent glands (the "castors") may still be worth more than a beaver pelt itself. Castoreum appeared in the materia medica until the 1700s, used to treat many different ailments, including headache, fever, and hysteria. The Romans believed the fumes produced by burning castoreum could induce an abortion; Paracelsus thought it could be used in the treatment of epilepsy ; and medieval beekeepers used it to increase honey production.

Castoreum, an anal gland secretion, appears to be used by beavers to mark their territory.

Castoreum is also used in small amounts to contribute to the flavor and odor of cigarettes.