It's time to let the cat out of the bag on this one - essential oils and carrier oils do not generally contain any Vitamin C!
We spoke with the lead chemists of some of our favorite essential oil testing facilities, and they confirmed that they do not generally see Vitamin C come up on the GC/MS reports for any of their essential oils or carrier oils. When it comes to citrus, for example, Vitamin C is mostly found in the juice of the fruits and not in the rind which the essential oil is distilled from.
Vitamin C is actually a water soluble, hydrophillic substance. This means that it is water-loving, and does not combine well with oil of any kind. It is true that some essential oils and carrier oils do contain vitamins and nutrients, but Vitamin C is just not one of them.
That being said, there are still a lot of immune-boosting and skin protecting properties that can be experienced from the terpenes that do naturally occur in essential oils.
Citrus oils in particular are very high in a chemical class called monoterpenes, which are known to boost immune function in the body.