Updated: Jun 22, 2018
This powerful protective blend is one my favourite essential oils for its smell and its versatility. I use it for hand sanitizer, as a non-toxic cleaner, in a diffuser to protect against environmental threats, and even as a sore throat gargle! Many of the oils in this blend are known for its immune supporting properties. But is there any research to back up these claims? Well I went looking...
One of doTERRA's most popular oils is On Guard, a proprietary blend of wild orange, cinnamon, eucalyptus, rosemary and clove essential oils. It is marketed as a support to healthy immune function and contains cleansing properties. In my search on pubmed I initially tried to find research on On Guard specifically. Surprisingly I did find this 2010 study which showed that this essential oil blend weakened the influenza virus in canine cells that were infected. It also appeared to reduce replication of the virus.
This lead to a study on a blend of 4 oils, 3 of which are present in On Guard - Cinnamon Bark (C. zeylanicum), Eucalyptus globulus and Rosemary oil Rosmarinus officinalis.
(Well, DoTERRA uses the species of eucalyptus - E. radiata instead of globulus but according to a quick search they have very similar chemical constituents. The blend in this study also included wild carrot oil).
Amazingly this study found that blend to be active against all fourteen bacteria strains tested, including some antibiotic‐resistant strains, and including S. aureus and S. pneumoniae! Plus it was also effective against the H1N1 and HSV1 viruses!
So how about the individual oils within On Guard or their chemical constituents? Does the research suggest they have antimicrobial activity? Meaning, can they fight against viruses, bacteria and/or fungi? Well a simple pubmed search revealed numerous studies. Though there was one down side. There weren't many human studies.
Antimicrobial activity was indicated for many of the individual oils and/or their chemical constituents within doTERRA On Guard. For example - this one on Clove bud, then this review on Cinnamon bark, this study on Rosemary Oil (and Clove) and finally Eucalyptus oil (which also had this one).