Peppermint oil is derived from the peppermint plant -- a cross between water mint and spearmint -- that thrives in Europe and North America. Peppermint oil is commonly used as flavoring in foods and beverages and as a fragrance in soaps and cosmetics. Peppermint oil also is used for a variety of health conditions and can be taken orally in dietary supplements or topically as a skin cream or ointment.