What is eugenol?

Eugenol is the chemical compound that forms the active ingredient in clove oil. In the United States, it is sold as an over-the-counter remedy for toothache pain. Dentists often use eugenol oil in temporary fillings to help alleviate potential physical discomfort in the gums.

Though it's primarily used in the United States for pain relief, eugenol is also found in cigarettes, where it acts as a menthol to reduce the harshness of the cigarette's smell and taste. It's possible to overdose on eugenol. When ingested excessively or improperly, eugenol may cause damage to the liver. Some people are allergic to eugenol.