Q&A: Oregano oil for allergies?

Some, but not enough to justify using it. A few test-tube studies have shown that high concentrations of oregano oil can kill some bacteria, fungi, and viruses. And one human study found that taking the oil orally helped to kill intestinal parasites. But swallowing oregano oil can cause upset stomach, diarrhea, and allergic reactions, and it could potentially damage the lining of the stomach and intestines. And we could find no evidence that the oil helps fight allergies.Your best bet is to rely on proven methods to fight both infection and allergies, and limit your oregano use to the actual spice—a potent source of healthful phytochemicals, research has found.

Got seasonal allergies? Take a look at our tips on how to fight hay fever, and find out what works best (subscribers only).