This kind of statement has always left me scratching my head. Sometimes it is also stated as "....EOs are the most OXYGENATED substances on earth." Whether its meant to be OXYGENATING or OXYGENATED the statement is just plain wrong. Yes essential oils contain oxygen but that doesn't equate to be "oxygenating" or the "most oxygenated." Those of you taking my Chemistry of Essential Oils course already know that, 99+% of the time, when we are talking about essential oil molecules, we are concerned only with 3 elements of the periodic table: Carbon, Hydrogen and Oxygen. The molecules in essential oils are mainly mono and sesquiterpenes and their oxygenated derivatives. Essential oils are volatile organic liquids. There are absolutely NO HORMONES (at least not human hormones) OR VITAMINS in essential oils. In addition, of these 3 most common EO elements, Oxygen is the LEAST frequently occurring. If you are just counting types of atoms in the essential oil molecules, Hydrogen is the most prevalent atom followed by Carbon, then Oxygen (again just counting numbers of atoms, not a weight comparison). A large percentage of all essential oil molecules are hydrocarbons (monoterpenes and sesquiterpenes) and don't even contain Oxygen at all. When the molecules do contain Oxygen, the ratio typically ranges from 1 or 2 atoms of Oxygen to say 10 to 17 atoms of Carbon and 18 to 26 atoms of Hydrogen (for the most common cases of oxygenated mono and sesquiterpenes). Furthermore, the Oxygen in essential oil molecules is BOUND OXYGEN not really available to be delivered in the form of free oxygen radical or oxygen molecules (of course there an infinitesimal amount of dissolved oxygen molecules in just about any liquid but this is insignificant) and thus not very "oxygenating." It is still unclear to me what the basis for these claims concerning essential oils are coming from and would love to know the literature sources that the claimants are citing as their support. I could go on more about this topic but Robert Tisserand has already written an excellent response to the "Oxygenating" myth on his website, so rather than re-invent the wheel I will refer all of you to read his comments there.