Spearmint Oil is produced by steam distillation of the flowering tops of the plants, which are partially dried prior to distillation.
The most abundant compound in spearmint oil is R-(–)-carvone, which gives spearmint its distinctive smell. Spearmint oil also contains significant amounts of limonene, dihydrocarvone, and 1,8-cineol. Unlike peppermint, spearmint oil contains minimal amounts of menthol and menthone. It is used as a flavouring for toothpaste and confectionery, and is sometimes added to shampoos and soaps.