High quality, pure oregano essential oil is extracted for the plant(Origanum vulgare ssp.hirtum), also know as the Greek oregano. If you feel a cold is round the corner, add 2-4 drops in a tub of boiled water, cover the head with a towel and inhale deeply. At any case, it should be used diluted, as it is caustic for the skin. It can be applied against lice. You can add a few drops in an essential oil diffuser or on a tea light lamp, it cleans the air and disinfects. You can also add 20 drops into 250ml distilled water and spray all surfaces of the household.