Thanks to its fresh, invigorating scent, peppermint essential oil is easily identifiable. However, it is peppermint oil’s constituents, such as menthol and menthone, that give it so many amazing health benefits in addition to its refreshing smell.
Menthol, the primary constituent in peppermint oil, is a powerful compound that has antibacterial, anti-inflammatory, antiviral, antispasmodic, and antiviral properties. Menthol is particularly beneficial for anyone suffering from both chronic and acute respiratory conditions, including asthma, bronchitis, sinusitis, hay fever, and the common cold. It is believed that menthol has the ability to inhibit the release of histamine . It also acts as a decongestant to relieve congestion, as well as an expectorant, which helps loosen and clear mucus in the airways, bronchi, and lungs.
On a side note, studies indicate that menthol may inhibit the growth of prostate cancer .
Research shows that the constituents in peppermint oil, including menthone, are particularly beneficial for anyone struggling with various stomach ailments, including irritable bowel syndrome (IBS). Although further research is needed to determine the exact mechanism by which peppermint oil helps relieve the abdominal pain and discomfort associated with IBS, numerous studies have shown that it does .
Menthone is also effective at decreasing smooth muscle spasms in the stomach by blocking calcium channels in the stomach . In addition, menthone can effectively relieve indigestion, nausea, and upset stomach, as well as nausea resulting from chemotherapy treatments.
 http://articles.mercola.com/sites/articles/archive/2013/10/14/peppermint-health-benefits.aspx  http://www.ncbi.nlm.nih.gov/pubmed/22437241  https://www.organicfacts.net/health-benefits/essential-oils/health-benefits-of-peppermint-oil.html  http://articles.mercola.com/herbal-oils/peppermint-oil.aspx