Clove Oil: Uses for Toothache, Eugenol, and How to Use It Safely

Clove oil is poisonous if swallowed, especially for children. Young children who swallowed it have developed liver failure, seizures and serious bleeding problems, in one case after about 10 mL. Store it out of reach.

What is clove oil?

Cloves are the dried, unopened flower buds of an evergreen tree native to tropical Asia, botanically Syzygium aromaticum. FDA's food regulations, which use the older name Eugenia caryophyllata, recognize essential oils made from three parts of the tree (the buds, the leaves and the stems) as well as eugenol itself, and allow all of them as food flavorings (21 CFR 184.1257).

Eugenol is the star. A 2021 review found it makes up at least half of clove essential oil, with most of the rest made of eugenyl acetate, beta-caryophyllene and alpha-humulene (Haro-González et al., Molecules, 2021). The same review notes that oil quality depends on the plant part and the tree: buds picked at the right stage from mature trees gave the best oil. That is why it is worth checking which part your bottle was distilled from.

Does clove oil work for a toothache?

Clove oil has a real numbing effect, but the evidence for treating toothache is thin.

The best human data come from a 2006 study in the Journal of Dentistry. Researchers applied a homemade clove gel, 20% benzocaine gel, or look-alike placebos to the gums of 73 adults, then gave each a small needle stick. Clove and benzocaine both reduced pain compared with placebo, and the two were not significantly different from each other (Alqareer et al., 2006). It shows clove can numb the gum surface, not that it fixes a toothache.

FDA looked at eugenol for over-the-counter toothache products decades ago. In a 1991 proposed rule on oral health care products, the agency noted that no clinical studies of eugenol had been submitted, said controlled trials were needed, and moved eugenol for toothache relief from Category I, where its advisory panel had placed it, to Category III, meaning more data were required (Federal Register, Sept. 24, 1991). The agency noted that eugenol can irritate the inside of the mouth, and comments in the same rulemaking raised the worry that it may harm the nerve of a tooth that is still alive.

Dentists do use eugenol, in a controlled way. Zinc oxide eugenol is a long-standing filling material for baby-tooth root treatments (Najjar et al., Clinical and Experimental Dental Research, 2019) and has been studied as a dressing for dry socket after an extraction (Cochrane, Daly et al., 2022). Those are professional materials, not a bottle of essential oil.

How to use clove oil for a toothache, short term

If you choose to try clove oil while you wait for a dental appointment, keep it small and brief:

• Use very little. A drop or two is plenty. The FDA panel's draft directions for a strong eugenol product called for 1 to 2 drops on a cotton pellet, held in the tooth cavity for about a minute and then removed, no more than four times a day.
• Keep it on the tooth. Eugenol irritates gums, cheeks and tongue. A cotton swab or small cotton ball helps you place it.
• Consider diluting it. Mixing it into a little plain carrier oil, such as a cold-pressed olive oil, can make it gentler on the surrounding gum.
• Don't swallow it. Stop if it burns, and don't use it in children.
• Book the dentist. FDA's reasoning is worth repeating: toothache relievers only buy time. The cause of the pain still needs treatment, and relief can tempt you to put off the visit.

Whole cloves, ground cloves and clove oil compared

For cooking, stick with whole or ground cloves rather than the oil. For more warm spices from South India, see our Kerala spices guide.

Clove oil safety

Children. The most serious reports involve children who swallowed clove oil. A 15-month-old in the UK developed sudden liver failure after drinking 10 mL and recovered after treatment with N-acetylcysteine, the same antidote used for acetaminophen overdose (Janes et al., European Journal of Pediatrics, 2005). A 2-year-old developed widespread clotting failure and liver cell death (Brown et al., Blood Coagulation & Fibrinolysis, 1992). Another case in Archives of Disease in Childhood described coma, seizures, a clotting disorder and liver damage (Hartnoll et al., 1993). The UK authors also found that home accidents involving aromatherapy oils rose fourteenfold between 1994 and 1999.

Liver. The published cases involve children, but they show how hard a swallowed dose of concentrated clove oil can hit the liver. It is not something to take by the spoonful.

Bleeding. In lab studies, eugenol and a related clove compound, acetyl eugenol, block platelets from clumping (Srivastava and Malhotra, Prostaglandins, Leukotrienes and Essential Fatty Acids, 1991). Effects in people aren't known, but if you take warfarin or another blood thinner, or have surgery coming up, ask your clinician before using clove oil regularly.

Mouth and skin. Eugenol irritates mucous membranes, which is why FDA's draft directions kept contact to about a minute. Dilute clove oil for skin use and patch test first.

Find it at William's

• Now clove oil, 1 oz: pure clove essential oil, steam-distilled from buds, leaves and stems.
• Earth's Care clove oil, 1 oz: steam-distilled from clove buds and sold for aromatherapy; its label says it is not for internal use.
• Starwest organic whole cloves (bulk): sold by weight, for chai, mulled drinks, and simmered dishes.
• Starwest organic ground cloves (bulk): sold by weight, for baking and spice blends.

If you're building a spice shelf, pair cloves with black pepper, another warm spice we carry in bulk.

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