At first glance, oregano seems like a spice to add to pizza sauce or a homemade Italian dish. After working with essential oils for a couple years, I have developed a notable appreciation for oregano essential oil. It is an antibacterial, anti-viral, anti-fungal, anti-parasite immunostimulant. In layman’s terms, oregano does not like the bad viruses and bacteria in the body, but supports the good ones. The main chemical composition in oregano essential oils is carvacrol, making it deter the growth of most bacteria without side effects. It can be used aromatically, topically, and internally, with a therapeutic grade of essential oil, as doTerra brand.
Personally, I do not diffuse oregano, as it is very strong. I have used it to cook, but note that it takes a tiny amount, so get some on a toothpick and not use as drops. Very strong. I do make up my cooty bomb sprays, which contain oregano. I also put 2 to 3 drops oregano essential oil in a veggie cap and fill with coconut oil for 10 day doses for GI issues, candida, and urinary tract infections. (Remember oregano attacks bad bacteria, virus, and fungus.) So I use it to cleanse. I can tell the difference in mental clarity and bloating. I have used topically on warts. It has reduced the wart, but you must remain diligent to eliminate completely.
Oregano, Wild Marjoram - Historic Usage
In ancient days it was used medicinally to cure an upset stomach, consumption, scurvy, jaundice, and to relieve toothaches, swellings and headaches. Greeks and Romans crowned young couples with garlands of oregano, and planted it on gravesites to provide happiness and peace. In colonial times it was used in much the same way as sweet marjoram but the flavor of the leaves was not considered as good in cooking. (from NPS.org)