Peppermint oil is simply the fragrant oil from the peppermint plant. It is used widely in all kinds of everyday products such as chewing gum and toothpaste. This wonderful natural remedy naturally tones the stomach, liver and intestines. It is also used to successfully treat ulcers, nausea, headaches, the symptoms of asthma, cystitis. It even has significant anti-viral properties too, used in the treatment of herpes.