Oregano is an herb that's commonly used in cooking. Oil extracted from its leaves has a long history of medicinal uses.
Over the centuries, it has been used to treat a variety of ailments, including snake and spider bites, respiratory troubles, and menstruation problems. Today, it is marketed for the treatment of a long list of health conditions.
The bark from some species of magnolia trees is used as a popular herbal treatment in traditional Chinese and Japanese medicine. In China, the herb is called Houpu.
The bitter-tasting bark contains at least 250 chemicals, several of which may be useful in treating health problems.
A single study found that taking 200 milligrams of oregano oil three times a day for six weeks eliminated three such parasites. But the study was small, inconclusive, and was funded by a supplement manufacturer.
Some laboratory studies show that oregano or its components have properties that can kill some food-borne germs. But there is no evidence that it helps prevent food poisoning.
Oregano oil has also been used to treat a condition that some alternative medicine practitioners refer to as yeast hypersensitivity syndrome. In this condition, an excess of the yeast candida albicans is thought to cause symptoms, such as sinus congestion, headache, fatigue, and depression. It is not a condition that is recognized by conventional medicine. And there is no evidence that oregano oil helps treat these symptoms.
Oregano oil in an oral form is also used to try to treat respiratory tract conditions such as:
Oregano oil is also marketed as an aid for:
Urinary tract infections
Oregano oil, when put into a form that lets it be applied to the skin, has been used to try to treat:
Marketers of oregano oil claim a host of other applications as well.
There is no research to back up these health claims.
Optimal doses of oregano have not been set for any condition. Quality and active ingredients in supplements may vary widely. This makes it very hard to set a standard dose.