Oil of Oregano Proves Effective Against Coronavirus

(EDITOR’S NOTE JAN 30, 2020: The following article, originally published in the Winter 2003 edition of Holistic Primary Care and posted to our site several years later, has received a lot of attention recently, owing to worldwide public concern about China’s coronavirus outbreak, and the Washington Post’s citation of this piece as an example of “fake news” about coronavirus.

Our article briefly described a preliminary in vitro experiment assessing the impact of carvacrol-rich oregano oil alone, or in combination with other monoterpene-rich herb oils, on the proliferation of coronavirus in human cell cultures. This pathogen was in the news back in 2003, because it was identified as the trigger for Severe Acute Respiratory Syndrome (SARS).

 The investigator, M. Khalid Ijaz, DVM, PhD, concluded that oregano oil can inhibit proliferation of coronavirus and reduce viral titers. However, he states clearly–as do we in our article–that this is early stage basic research, and that we would need an actual human trial before drawing any firm conclusion about the clinical role of oregano oil for coronavirus infection.

To the best of our knowledge, this research has not yet been done.

But it should be done. Given the epidemic potential of the current coronavirus outbreak, and the fact that the efficacy of existing antiviral drugs against this strain is largely unknown, we ought to  study all potential options, even if they fall outside the scope of conventional drug-based medicine. A number of preliminary in vitro or animal studies have shown that compounds in oregano oil are virustatic and virucidal against several viral pathogens. There are plausible mechanisms of action. We should not rule out oregano oil simply because it is derived from an herb.

We stand by our original 2003 article. The Washington Post’s insinuation that our coverage of Ijaz’ study 17 years ago constitutes “fake news” is misguided and short-sighted.–Erik Goldman, Editor)


Oil of oregano may prove to be a valuable ally against Severe Acute Respiratory Syndrome (SARS).

A recent in vitro study indicates that the essential oil of this medicinal herb can destroy human coronavirus, thought to be the pathogen responsible for SARS, and completely stop its replication within 20 minutes of exposure.

The study was conducted by Dr. M. Khalid Ijaz, of Microbiotest, an independent microbiological testing lab in Sterling, VA. Dr. Ijaz incubated human coronavirus in MRC-5 cell lines with Oreganol P73, an olive-oil preparation of wild oregano, and with Oregacillin, a combination of wild oregano, wild sage, wild cumin and wild cinnamon oils. Both products are made by Physician’s Strength/North American Herb and Spice, a company that specializes in medicinal essential oils from the Mediterranean.

The oregano oil alone reduced viral titers from over 5 million particles per ml at baseline, to 167 particles per ml within 15 minutes. At 20 minutes, the titers were down to 150 particles per ml. The Oregacillin combination reduced titers from over 5 million, to 133 particles per ml in 15 minutes. Within 20 minutes, they were reduced to non-detectable levels. The investigators noted that both preparations were able to halt viral replication within the host cells.

The in vitro findings need to be confirmed in human clinical trials, but they are compelling in that they show that oil of oregano, alone and in combination with other essential oils, have unequivocal virucidal and virustatic effects. Both Oreganol P73 and Oregacillin are available from Physician’s Strength (800-243-5242).

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