Mint (family Lamiaceae) has some useful medicinal properties. This is based on the content of volatile oils that it contains. Peppermint is not a species but a hybrid cross between watermint and spearmint. Because it is a hybrid it is generally sterile and does not reproduce by production of seeds, but only vegetatively. Peppermint is particularly helpful as a digestive relaxant because of the menthol it contains. Crushing the leaves releases the menthol which has been shown through peer reviewed science to be effective at causing relaxation of smooth muscle. This makes it a useful treatment for stomach cramps and other maladies associated with gastrointestinal spasm. Peppermint tea is effective because the dried leaves retain around 0.5 % of the total volatile oil content, of which around half is menthol. However, enteric coated capsules that deliver the menthol to the distal part of the gut before releasing their content are also available. As well as menthol, other volatile oils include menthone and menthyl esters such as menthyl acetate. Garden mint, Mentha sachalinensis, is easy to grow and has a similar volatile oil content to peppermint.
