Oil of Oregano

Oil of Oregano: Overview

Oil of Oregano is a potent antiseptic used both topically and internally.  Research demonstrates that it is effective in killing a range of organisms, especially yeast and bacteria.

Diagnose your symptoms now!
  • check your overall health status
  • have a doctor review your case (optional)
  • learn what you should be doing right now

The smell of oregano is common in Italian, Mediterranean, North African and Mexican cooking establishments.  Oregano is a name for several different species of plants, with similar characteristics.  True wild oregano (sometimes called wild marjoram) is the species Origanum vulgare.  Marjoram (Origanum majorana) or Mexican Oregano (Lippia graveolens) are often used in place of the true oregano species with varying degrees of medicinal similarity.

While the 'killing action' of oregano oil in many studies was the result of activity in a "test tube" or culture media, enterically coated products will deliver the oil into the GI tract.  As at the time of writing, these antibacterial actions have not yet been confirmed by human clinical trials.

History; Source

Oregano leaves have been used traditionally for almost every ailment concerned with the respiratory and digestive system.

Oil of oregano is not to be confused with common oregano in the kitchen spice cupboard, which is usually Oregano marjoram rather than true oregano (Oregano vulgare).

The essential oil distilled from oregano leaves contains varying amounts of thymol and carvacrol which can constitute as much as 90% of the oil.  One should be sure to get oregano oil from a reputable company, for it has been suggested that many of the oils available commercially are derived from non-oregano species, particularly various types of marjoram and thyme.  Furthermore, there are different concentrations of oregano oil available that are being made with different extraction techniques which may involve the use of solvents.


Most of the activity of oregano comes from the volatile oils including thymol, carvacrol, p-cymene and others.  Some of these volatile oils have been shown to have strong antifungal and anthelmintic ("anti-worming") activities.


Typical doses, depending on the concentration, are 1-4 drops, capsules or tablets; 1-4 times per day.  Full strength oregano oil is quite irritating and should never be ingested without diluting.

You can try adding bulk oregano oil to capsules when taking it internally, starting with a small amount and increasing it slowly.  It is best when taken with food but since this volatile oil is quickly absorbed and associated with inducing heartburn, some may require them to be taken in coated capsules, so they do not break down in the stomach but instead are delivered to the small and large intestine.  This also delivers the oil further down in the GI tract, where its killing action may be needed.

When using pure oregano oil topically, make sure to dilute it in a carrier oil such as almond, olive, or another pure vegetable oil to avoid burning the skin.  Avoid canola oil and Wesson or other commercial vegetable oils.

Side-Effects; Counter-Indicators and Warnings

Side-effects are minimal, but allergic reactions to oregano oil and a sensitivity to plants in the same family (thyme, basil, hyssop, marjoram, mint, sage) can occur.  It should not be applied in full strength to the skin.

Oil of oregano may reduce the absorption of iron, so take the oil at least two hours before or after consuming iron supplements.

References & Further Information

The body of positive evidence for oregano oil as a major antibiotic is growing.  Among 52 plant oils tested, oregano was considered to have "pharmacologic" action against common bugs such as Candida albicans (yeast), E. coli, Salmonella enterica and Pseudomonas aeruginosa. [Journal Applied Microbiology, Volume 86, June 1999]  Pseudomonas is a type of germ that is getting more difficult to treat as it has developed strains that are resistant to antibiotic drugs.

  • Oil of oregano at relatively low doses was found to be efficacious against Staphylococcus bacteria and was comparable in its germ-killing properties to antibiotic drugs such as streptomycin, penicillin and vancomycin. [Science Daily 10/11/2001]
  • Researchers at the Department of Food Science at the University of Tennessee reported that, among various plant oils, oil of oregano exhibited the greatest antibacterial action against common pathogenic germs such as Staph, E. coli and Listeria. [Journal Food Protection, Volume 64, July 2001]
  • British researchers reported oregano oil had antibacterial activity against 25 different bacteria. [Journal Applied Microbiology, Volume 88, February 2000]
  • Of more recent interest are reports showing that carvacrol from oil of oregano kills spores, such as Bacillus cereus and Bacillus anthracis (anthrax). [Archives Microbiology, Volume 174, October 2000; Quarterly Review Biology, Volume 73, March 1998] Bacillus cereus is considered to be from the same species as Bacillus anthracis
    (anthrax). [Applied Environmental Microbiology, Volume 66, June 2000]  In tests of antibiotics and antiseptics, Bacillus cereus is often used in studies in lieu of the anthrax strain. [University of Michigan News & Information Service, Sept. 23, 1998]
  • The growing problem of antibiotic resistance has health authorities extremely concerned.  It is already the case that various germs are showing resistance to vancomycin, particularly to intestinal bacteria (Enterococcal species) among hospitalized patients. [Southern Medical Journal, Volume 94, August 2001]
  • Vancomycin is considered to be the most potent antibiotic available and is withheld from use as a drug of last resort.  Drug resistance does not develop against naturally-occurring antibiotics such as garlic and oil of oregano.

On This Page

Oil Of Oregano:

Oil of Oregano can help with the following:

Dental / Oral

Periodontal Disease - Gingivitis

Dilute oregano oil in a small amount of water and dab onto the affected tissues 3-4 times per day to kill the bacteria causing inflammation.


Blastocystosis (Blastocystis hominis)

One study investigated the use of oregano oil in the treatment of GI parasites in 14 adult patients.  After 6 weeks of treatment, there was a complete disappearance of Entamoeba hartmanni in 4 cases and Blastocystis hominis in 8 cases.  Gastrointestinal symptoms improved in 7 of the 11 patients infected with B. hominis. [Phytotherapy Research. 2000; 14: pp.213-4]

Yeast / Candida Infection

Place 3 drops of oregano oil into an empty gelatin capsule (or vegicap), or mix the same amount of oil into juice and take 3 times each day.  Enteric-coated preparations are available at about 50-100mg of oil per capsule or tablet.  Several weeks of continuous use may be required for the anti-fungal properties of oil of oregano to clear up a deep-seated Candida infection.

Fungal Skin / Nail Infection

Oregano oil is an excellent topical agent for toenail and fingernail fungus.  Highly diluted oil may also be taken internally for the same conditions.

Athletes Foot

Rubbing a drop or two of oregano oil into an area that is itching from athlete's foot may help resolve the problem, but caution is advised when using it topically as it can burn the skin when too concentrated.

Report by The Analyst™
Click to see sample report
Health problems rarely occur in isolation or for obvious reasons

Your body is a highly complex, interconnected system.  Instead of guessing at what might be wrong, let us help you discover what is really going on inside your body based on the many clues it is giving.

Our multiple symptom checker provides in-depth health analysis by The Analyst™ with full explanations, recommendations and (optionally) doctors available for case review and answering your specific questions.


May be useful: may help with
May be useful:
may help with
Moderately useful: often helps with
Moderately useful:
often helps with
Very useful: is highly recommended for
Very useful:
is highly recommended for
We use cookies for traffic analysis, advertising, and to provide the best user experience