Oil of clove, also known as clove oil, is an essential oil extracted from the clove plant, Syzygium aromaticum.[1] Clove oil is commonly used in aromatherapy and for flavoring food and some medicines.[2] Madagascar and Indonesia are the main producers of clove oil.[3]
Some countries, such as the UK, acknowledge its use for temporary relief of toothache,[4] although there is insufficient medical evidence to support its use as an analgesic.[1][2]
There are three types of clove oil:[3]
Distilled clove oil from buds contains mixed phytochemicals, including as main constituents phenylpropanoids (primarily eugenol), carvacrol, thymol, and cinnamaldehyde, with smaller quantities of polyphenols, carbohydrates, lipids, oleanolic acid, and rhamnetin.[1]
Clove oil is toxic in anything other than small therapeutic doses, and several cases of acute liver and kidney damage have been reported, principally in children.[5]
Particularly in South Korea and India, eugenol, a phytochemical extracted from clove oil, is used to relieve toothache.[6] Applied to a cavity in a decayed tooth or tooth socket remaining after extraction, eugenol or clove oil may relieve toothache temporarily.[6] In the United States, the FDA considers eugenol ineffective for treating dental pain, and has downgraded clove oil as an analgesic due to insufficient evidence to rate its effectiveness.[2]
Eugenol is a reliable source for producing natural vanillin (by the US definition). It is a versatile molecule, which can be converted to vanillin with a few simple steps of conversion through the use of naturally available phytochemicals.
Clove oil is commonly used to anesthetize or euthanize laboratory or pet fish.[7][8]
Clove oil is a component of choji oil (Japanese: 丁子油), which was traditionally used for the maintenance of Japanese swords.[9][10]
In Germany, Commission E permits the sale and administration of clove oil as a medicinal herb.[11]
Clove oil and eugenol, one of the chemicals it contains, have long been used topically for toothache, but the FDA has reclassified eugenol, downgrading its effectiveness rating. The FDA now believes there isn't enough evidence to rate eugenol as effective for toothache pain.