Find out 10 Essential Oils shown in laboratory studies to have the most potent, broad spectrum antibacterial activity.

What is an antibacterial?

Anything that destroys bacteria or inhibits the growth of bacteria or its ability to reproduce is an antibacterial. 

Studies have confirmed that essential oils can be used as a natural complementary alternative to synthetically produced antibiotic medications. In recent years there has been a growing body of evidence supporting the use of essential oils as antimicrobials. 

The Research Finding on 10 Essential Oils

1 - Essential Oils Shown to be Effective for 22 Strains of Bacteria

In vitro studies of 22 strains of bacteria showed that Lemongrass (Cymbopogan flexuosus), Eucalyptus (Eucalyptus globulus), Peppermint (Mentha x piperita) and Orange (Citrus sinensis)  oils were effective against all 22 bacterial strains. 

Lemongrass (75% citral)

Another study on Lemongrass and pure citral on their antibacterial activity for multi-drug resistant bacteria, such as MRSA, “Highlights [Lemongrass] potential for use in the management of drug-resistant infections.” Lemongass flexuous is 85% citral.

Eucalyptus

The results of a study on Eucalyptus globulus showed that E. globulus might be useful as a natural antibiotic for the treatment of several infectious diseases caused by E. Coli and Staphlococcus aureus. 

Peppermint

A study on the Antibacterial Properties of Peppermint Essential Oil for wound healing applications showed bacterial inhibition was effective when used.

Sweet Orange

A study on Orange oil’s effectiveness as an antibacterial agent was studied for Salmonella. The study showed Orange oil (composed principally of d-limonene, 94%, and myrcene 3%) as an all natural antibiotic. 

2 - Essential Oils Shown to Be Effective for 21 Strains of Bacteria

The next level of effectiveness in the same in vitro study showed that Aegle (Aegle marvelous (L.) Correa and Palmarosa (Cymbopogan martinii) oils inhibited 21 strains of bacteria.

Palmarosa (80-90% geraniol)

Another study on the antibacterial activity of four essential oils (palmarosa, lavender, tuberose and evening primrose) supported these results with reports that the essential oil of palmarosa exhibited the most potent antibacterial activity among all the essential oils tested. 

3 - Essential Oils Shown to Be Effective for 20 Strains of Bacteria

Other essential oils in the in vitro study showed Patchouli and Ageratum (Ageratum conyzoides L.) oils inhibited 20 strains of bacteria.

Patchouli

Additional studies evaluating the antibacterial activity of patchouli oil proved that [Patchoul] has strong antibacterial effects. 

4 - Essential Oils Shown to Be Effective for 15 and 12 Strains of Bacteria

The in vitro study concluded with results for Geranium (Pelargonium graveolens) and Citronella (Cymbopogon nardus) oils showing each was inhibitory to 15 and 12 bacterial strains, respectively, of the 22 strains of bacteria studied.

Geranium (14% geraniol and 35% citranellol)

A study of the antibacterial activity of geranium oil showed the “Pure essential oil to exhibit the most extensive inhibition zones.” Geranium was also shown to be more effective as an antibacterial agents that both chloramphenicol and amoxicillin. The most susceptible strain of bacteria was Staphylococcus aureus. 

Citronella

Its major component, geraniol, was tested and shown active as an antibacterial agent. Both Citronella and geraniol were shown to be effective bactericidal agents against ataphlococcus aureus.\

Discussion for both Aegle (Aegle marvelous (L.) Correa and Ageratum (Ageratum conyzoides L.).

Both of these oils, though included in this in vitro study, are not readily available oils, at this time. However, they have been studied and found viable therapeutic agents for treating a variety of bacterial infections.

Aegle is a “sacred medicinal and nutraceutical tree of India” and has a long history of use. 

Ageratum, also known as billy-goat weed, is native to South America. It is now, however, grown in many Asian countries, including Nepal, where it is used traditionally for many therapeutic purposes. Another study conducted on the plant showed little efficacy for use as an anti-bacterial, so more data needs to be collected on Ageratum for use as an anti-bacterial agent.