The side effects of taking Oreganol P73 oregano oil may include gastrointestinal upset, allergic reactions and an increased risk of bleeding for people with blood clotting disorders. According to WebMD and Science Based Medicine, there is insufficient scientific evidence to prove any positive or detrimental effects of oregano oil.
As detailed on OreganoPro.com, Oreganol P73 is a cold-pressed, edible oil of oregano manufactured by North American Herb and Spice. WebMD notes that there has not been enough research done to determine what, if any, side effects are associated with the oil's consumption. Women who are pregnant or breastfeeding should avoid oil of oregano, as there is some concern that large quantities of oregano may cause miscarriage.