Peppermint also known as M. balsamea Willd is a hybrid mint, a cross between watermint and spearmint. The plant, indigenous to Europe and the Middle East, is now widespread in cultivation in many regions of the world.

Peppermint oil is under preliminary research for its potential as a short-term treatment for irritable bowel syndrome.

According to the German Commission E monographs, peppermint oil (as well as peppermint leaf) has been used internally as an antispasmodic (upper gastrointestinal tract and bile ducts) and to treat irritable bowel syndrome, catarrh of the respiratory tract, and inflammation of the oral mucosa. Peppermint oil may also act as a carminative, cholagogue, antibacterial, and secretolytic, and it has a cooling action. Externally, peppermint oil has been used for muscle pain and nerve pain.

Enteric-coated peppermint oil capsules (Colpermin) have been used as an orally administered antispasmodic premedication in colonoscopy. The capsules were found beneficial in reducing total procedure time, reducing colonic spasm, increasing endoscopist satisfaction and decreasing pain in patients during colonoscopy.

Peppermint has a long tradition of use in folk medicine and aromatherapy. Peppermint is commonly thought to soothe or treat symptoms such as nausea, vomiting, abdominal pain, indigestion, irritable bowel, and bloating, although most of these effects have not been adequately demonstrated in human research

The aroma of peppermint has been studied for its possible memory and alertness enhancing properties, although other research contests this.

Peppermint oil is also used in construction and plumbing to test for the tightness of pipes and disclose leaks by its odor.