4- Peppermint (Mentha x Piperita)
Peppermint is the most effective stomach-calming herb you can use, and it quickly relieves the upset stomach.
Moreover, peppermint oil, which is in the form of enteric-coated capsules, is extremely efficient in treating irritable bowel syndrome (IBS).
These capsules, since coated, go through the stomach and open in the intestines, have a strong antispasmodic activity on the muscles and prevent constipation and diarrhea.
If you want to calm the upset stomach, you can drink a cup of peppermint tea, and in the case of IBS, you should take a capsule of 0.2 milliliters of peppermint essential oil 1-3 times daily with water and before meals.
Caveats: Snow warns that“Peppermint will cause heartburn and worsen acid reflux in some people,” so avoid this herb if you suffer from these issues.