Oregano oil is a powerful, plant-derived essential oil that may rival antibiotics when it comes to treating or preventing various infections. In fact, it contains properties that are antibacterial, antiviral and anti-fungal.  And oregano essential oil is unlikely to cause many of the harmful side effects that are commonly attributed to high use of antibiotics — such as increased risk for antibiotic resistance, poor gut health due to destroying beneficial pro-biotic bacteria, reduced vitamin absorption and leaky gut syndrome due to damage of the GI tract’s lining.