On Guard is Doterra's spin on the traditional Four Theives blend of essential oils; wild orange, clove, cinnamon, eucalyptus, and rosemary.
The Four Theives blend comes from a tale about a mysterious recipe originating in the 15th century. Supposedly, this blend was created by a group of grave robbers to protect themselves from contracting the plague while they stole from the bodies of the ill and deceased. When they were cought, the theives gave over their recipe to the law in order to receive a lesser punishment.
As the legend has it, these essential oils are highly immune boosting, anti-viral, anti-bacrerial and anti-mocribial.
I use this oil in my practice by diffusing it throughout the day, to purify the air and promote an uplifting aroma. It can also be added to surface cleaner to amplify it's cleaning properties.