Carrier oils are a substance that can, well, carry essential oils onto your skin. Essential oil expert, author, and teacher Amy Galper defines them as any sort of lipid-rich extract that can be expelled from a seed, nut, or fruit. Read: They’re the fatty, rich plant oils that you probably already have in your kitchen.
Essential oils, on the other hand, are made from the isolated aromatic compounds of a plant, which are fragrant but volatile. They’re really concentrated—but also really prone to evaporate quickly, so they can’t be absorbed by the skin like a carrier oil can.
“If we want to apply an essential oil to our physical body, the only way we’re going to get it in our body to make physiological change is to mix it in with something that it dissolves in well,” Galper tells mbg. That’s where the carrier comes in, which does double duty of feeding and nourishing the skin while helping deliver the therapeutic properties of essential oils.
Carrier oils are also important from a safety perspective. Since essential oils are so potent, they can irritate (and in some cases, really do damage to) the skin when applied on their own, or “neat” as it’s known in aromatherapy land.
“It’s not advisable to put essential oils directly on your skin,” Galper stresses. “It’s always recommended, for safety measures, to add or dilute them down in a carrier oil.”
Vannoy Gentles Fite, author of Essential Oils for Healing, adds that diluting essential oils in a carrier oil will also help them last longer. This means that there’s a financial case for carrier oils—most of which are more affordable than the essential oils they transport.