Benefits Of Healthvit Evening Primrose Carrier Oil, also known as base oil or vegetable oil, is used to dilute essential oils before they are applied to the skin in massage and aromatherapy. They are so named because they carry the essential oil onto the skin. Carrier oils do not have aroma though some have a mild distinctive smell. Soul flower cold processed hexane free carrier oils are as natural & unadulterated as possible. Cold-pressing is the purist method of producing carrier oils & cold pressed oils retain much more of their valuable nutrients.