Eucalyptus Oil

For many years, eucalyptus oil has been used to relieve coughing. Today, some over-the-counter cough medications have eucalyptus oil as one of their active ingredients.
Vicks VapoRub, for example, contains about 1.2 percent eucalyptus oil along with other cough suppressant ingredients.

The popular rub is applied to the chest and throat to relieve cough symptoms.