Allergy Research Group Oregano Oil is a dietary supplement to offer fungal and bacterial level support. Oregano oil, a pure essential oil, is a powerful antioxidant that can be applied topically as well as ingested dependent on the need. It supports prevention and treament of some bacterial, fungal and immune ailments as well as reducing skin inflammation from UV rays. Pure essential oil of oregano derived from Origanum vulare, containing 65% carvacrol.