NSP's Guardian essential oil combines oils that work together to fight infectious germs. Using an aromatherapy diffuser to disperse minute particles of the oil blend into the air is one of the most effective ways to use Guardian. In addition, you can use a spray bottle to "mist" the air, dampen a cloth with Guardian and place it in front of an air vent; or even just inhale the oils directly from the bottle. This is one of the best natural remedies I've found for preventing and also shortening the duration of illness.