Oregano, also called origanum vulgare, is an aromatic perennial plant whose oil has been found to be useful in maintaining a healthy digestive tract, reducing the number of unhealthy microbes in the intestines and providing beneficial antioxidants. While oregano has long been used as a cooking herb, it also has been revered for centuries by various civilizations for its healthful properties.
Pure essential oil of oregano should not be ingested, but a number of companies have incorporated a small, diluted amount of the oil into capsules that are safe to consume.
Oregano is known as wild marjoram in Europe. It has been used by ancient Egyptians as an emollient and preservative. Ancient Greeks believed the goddess Aphrodite created it as a symbol of happiness. Oregano has been used for centuries by Spaniards, Mexicans, Italians, and more recently, Americans for the aromatic flavor it imparts to food.
The oil has long been used in folk remedies as a soothing digestive aid. It is also used in remedies for seasickness, indigestion, cough and other respiratory ailments. This volatile oil is also widely used in soaps, lotions and even as an ant repellent.
There only have been a few laboratory studies conducted on the effects of oil of oregano. One study, published in the February 2000 issue of the Journal of Applied Microbiology, indicates it has properties that inhibit the growth of bacteria. A study published in the July 1982 issue of Planta Medica verified the oil's ability to reduce intestinal spasms.
In the June 2004 Journal of Ethnopharmacology, researchers found giving mice oil of oregano supplements reduced blood glucose levels, offering some hope for diabetics. Several studies published on Drugs.com also show it has anti-fungal, antioxidant and anti-parasitic properties, mainly due to its major chemical components thymol and carvacrol.
Interactions With Medications
There have been no documented interactions with other medications. But according to the American Herbal Products Association’s Botanical Safety Handbook, because volatile oils are highly concentrated, further studies are needed. Due to its prevalent use in cooking, the Food and Drug Administration has designated it as "generally recognized as safe".
No standard dose exists for oil of oregano because of the lack of clinical studies. Since the oil can cause digestive complaints, Gaia Herbs, a leading manufacturer of organic herbs since 1986, recommends taking the supplement for no more than four weeks at a time and that only one 460 mg tablet be taken no more than twice daily.
Researchers in a 2000 study published in Phytotherapy Research administered a daily dosage of 200 mg emulsified O. vulgare oil for six weeks to patients with parasitic infections. Seven of 11 patients with a specific parasite showed marked improvement.
Oil of oregano can also be applied topically. Follow the manufacturer's directions or consult a medical doctor or homeopathic practitioner for proper dosing or application instructions.
Allergic dermatitis can occur with topical application of oil or oregano. Ingesting large quantities has been shown to cause eczema, digestive complaints, headache, anorexia and nervousness. Rarely, a severe reaction causing difficulty breathing can occur. Because testing has been minimal, avoid using the oil if you are pregnant or nursing.