Eucalyptus Oil
Eucalyptus oil contains several compounds that relieve symptoms of the common cold. The water-soluble compound 1,8-cineole is the main active ingredient in eucalyptus oil. It has been shown to kill the respiratory syncytial virus (RSV), a common cause of croup and pneumonia in children. It has also been shown to reduce mucus production when inhaled.
Eucalyptus oil’s antiviral properties are largely due to its 1,8-cineole content. The extracts of eucalyptus leaves were found to be effective at inhibiting the growth of the respiratory syncytial virus. In addition, they were effective against several bacteria, including giardia lamblia and pseudomonas aeruginosa.
Because eucalyptus oil can help with runny nose and cough, you can blend it into steam inhalations for sinusitis, bronchitis, acute asthma, laryngitis, and other conditions that tend to cause mucus production.