Georgetown University Medical Center • February 9, 2024

Oregano Oil May Protect Against Drug-Resistant Bacteria, Georgetown Researcher Finds

Oregano Oil as Antibacterial and Antibiotic Alternative

Oil from the common herb oregano may be an effective treatment against dangerous, and sometimes drug-resistant bacteria, a Georgetown researcher has found. Two studies have shown that oregano oil--and, in particular, carvacrol, one of oregano's chemical components--appear to reduce infection as effectively as traditional antibiotics.

A small green plant is growing in a pot

Oil from the common herb oregano may be an effective treatment against dangerous, and sometimes drug-resistant bacteria, a Georgetown researcher has found. Two studies have shown that oregano oil—and, in particular, carvacrol, one of oregano’s chemical components—appear to reduce infection as effectively as traditional antibiotics. These findings were presented at the American College of Nutrition’s annual meeting October 6 and 7 in Orlando, Fla.


Harry G. Preuss, MD, MACN, CNS, professor of physiology and biophysics, and his research team, tested oregano oil on staphylococcus bacteria—which is responsible for a variety of severe infections and is becoming increasingly resistant to many antibiotics. They combined oregano oil with the bacteria in a test tube, and compared oregano oil’s effects to those of standard antibiotics streptomycin, penicillin and vacnomycin. The oregano oil at relatively low doses was found to inhibit the growth of staphylococcus bacteria in the test tubes as effectively as the standard antibiotics did.


Another aspect of the study examined the efficacy of oregano oil and carvacrol, which is believed to be the major antibacterial component of oregano, in 18 mice infected with the staph bacteria


Six of the mice received oregano oil for 30 days, and 50% of this group survived the 30-day treatment. Six received the carvacrol in olive oil, not oregano oil, and none survived longer than 21 days. Six mice received olive oil alone with no active agents (the control group) and all died within three days. A repeat study corroborated these findings, which demonstrates that there are components of oregano oil other than carvacrol that have antibiotic properties.


“While this investigation was performed only in test tubes and on a small number of mice, the preliminary results are promising and warrant further study,” Preuss said. “The ability of oils from various spices to kill infectious organisms has been recognized since antiquity. Natural oils may turn out to be valuable adjuvants or even replacements for many anti-germicidals under a variety of conditions.”


This study was sponsored by Waukegan, Ill.-based North American Herb and Spice.


Georgetown University Medical Center includes the nationally ranked School of Medicine, School of Nursing and Health Studies, and a biomedical research enterprise. For more information, please visit http://www.georgetown.edu/gumc


Georgetown University Medical Center. "Oregano Oil May Protect Against Drug-Resistant Bacteria, Georgetown Researcher Finds." ScienceDaily. ScienceDaily, 11 October 2001.

A bottle of essential oil is surrounded by bugs and leaves.
By Mediterranean Oregano Oil January 28, 2025
A study found that taking 200 milligrams of oregano oil three times a day for six weeks got rid of three intestinal parasites. This has made people interested in oregano oil as a natural way to treat parasites. Oregano oil has a long history of being used for health, making it a good choice for those looking for natural treatments . To learn more and buy high-quality oregano oil, visit https://www.oiloforegano.com/order. Oregano oil can fight parasites, making it a natural remedy for infections. As more people look for natural ways to treat parasites, oregano oil is becoming more popular. It's good at targeting parasites, which makes it a strong option for treatment. 
A close up of a plant with green leaves
October 28, 2024
As posted at National Library of Medicine