Oil of Oregano and Herpes

Oregano, a cooking spice often used in Italian sauces, may do more than liven up your pizza or spaghetti. Oil of oregano could have antimicrobial properties that can destroy bacteria, fungi and viruses, including the family of Herpes simplex viruses that can cause cold sores, shingles and genital herpes. Oil of oregano has a long history of use both in ancient and alternative medicine. While laboratory studies have shown oil of oregano to have antimicrobial benefits, human studies to determine actual benefit are lacking.

Ingredients

Oil of oregano comes from a number of types of oregano plants that contain varying amounts of its active ingredients. The ingredients thought responsible for its possible anti-viral benefits, called phenols, include carvacrol and thymol. Most oregano sold in the United States and Europe comes from the Origanum vulgare plant. Manufacturers usually mix oil of oregano with olive oil, which improves its absorption and also makes it less caustic and safe for human use, oil of oregano manufacturer Hedd Wyn Essentials explains.

Studies

Turkish researchers tested components from one type of oregano, from the plant Origanum acutidens, in the laboratory against Herpes simplex virus type 1 cells. Methanol extracts from the plant had an anti-viral effect, inhibiting replication of the HSV-1 virus, researchers reported in the June 2004 issue of the "Journal of Agriculture and Food Chemistry."

Concerns

Many substances that can kill microbes in the laboratory do not have the same effect when taken by real people, pharmacist Scott Gavura warns on the Science-Based Medicine website. High doses used in a laboratory to kill viruses such as the herpes virus might prove toxic in people. Oil of oregano may also not reach the target cells to kill the virus.

Caveats

Oil of oregano can cause minor skin irritation when applied to mucous membranes at concentrations higher than 1 percent, according to an article published in the May/June 2010 issue of "Nutrition Today." The German regulatory agency Commission E, which oversees the use of herbs, does not recommend oil of oregano for medicinal purposes, stating that its effectiveness has not been established. Although alternative medicine sites proclaim that oil of oregano cures herpes, their evidence is all anecdotal or from laboratory studies only.