Many of these oils are mixed with petroleum, so don't. If it were pure, then it would not harm you; but it is very likely that it is mixed down to around 4-7% of the actual oil that you want.
(Another answer - former vitamin dept. manager) - Essential oils used in aromatherapy are NOT appropriate for ingestion.
What you're looking for is food-grade (capsule or liquid) oregano oil. The most popular vitamin (internal) one that I carried was called Oreganol (liquid) and OregaMax (capsule), made by North American Herb and Spice. Those are commonly used by folks who are looking for the immune system-supporting effects of oregano oil. Some essential oils in pure form are ok to ingest, but in very small amounts and diluted with alcohol or water, and always under supervision of certified health care practitioner.
Not to be use by pregnant or nursing women, those with damaged or sensitive skin or children under 2 years. Never use undiluted. Use only pure essential oil. Controvery over internal use. And more . . .
It might be dangerous to ingest it since it contain erucic acid. You can refer to an article here to read about it. http://tucsoncitizen.com/wryheat/2011/04/04/jojoba-oil-good-on-the-outside-bad-on-the-inside/
The difference between oil of oregano and oregano oil is nothing! One can use both types and the terms are interchangeable. Oregano oil or oil of oregano are great additions to cooking.
oil of oregano
If you are referring to oregano-infused oil, it is most common to use olive oil. But there is such a thing as pure oregano oil (pressed from oregano), but that is a nutritional supplement and not typically used for cooking.
I have used essential oils professionally for more than 20 years for products at vivantnatural.com. While there are a few essential oils that are safe to ingest, there are many more that should not be ingested. It is good practice not to take essential oils orally, but rely on the essential oils in the herb itself. That would be far safer. Dogs can eat oregano, garlic, and many other herbs.
You could take 500-1000 milligrams of Oil of Oregano for this condition. Too much oil of oregano can irritate the stomach lining.
Aromatherapy candles can be made from beeswax, soybean wax, vegetable oil with pure essential oil. But the best is to made aromatherapy candles from soy because they're all natural.
Ginger oil is an essential oil that is used in today's aromatherapy.
Aromatherapy.
Aromatherapy, on the other hand, relies on the essential oil extracted from the peel.
Almond oil is used as a carrier oil in aromatherapy. Essential oils need to be mixed into a carrier (base) oil since most of them are too potent and concentrated to be used undiluted on the skin. There are 2 forms of almond oil: bitter (known as just "almond oil") and sweet. Sweet almond oil is preferred by most aromatherapists and can be used in aromatherapy recipes for children.
I think this is one of the most unique uses of oil of oregano. Imagine a natural mosquito repellant without using strong DEET's and other pesticides. Oregano oil was shown in studies to be an effective natural mosquito repellant. This study found Oil of Oregano repels mosquitoes better than traditional chemical repellants like DEET. Research has shown a solution of 2% oregano oil makes an effective mosquito repellant. Another great use of oil of oregano.Reference: http://www.healthy-oil-planet.com/uses-of-oil-of-oregano-2.html