A carrier oil is an oil that is used to dilute essential oils for the purpose of aromatherapeutic treatments. Most aromatherapy carrier oils are derived from nuts, fruits, and vegetables. The oil from nuts is usually expressed from the meat of the nut and not the shell. When aromatherapy carrier oils are expressed from vegetables and fruits they are often expressed from the seeds within the plants.
Aromatherapy carrier oils are almost always used in treatments in which the essential oil is applied to the skin. This may be in treatments such as aromatherapy baths or massage therapy that incorporates aromatherapy. This is also often the case in aromatherapy products, such as lotions and balms, that are intended for use on the skin. Most essential oils are too strong to use directly on the skin. Some essential oils can be irritating to the skin or, in the case of some citrus oils, create strong photosensitivity in the skin if they are not diluted.
The purpose of aromatherapy carrier oils is to dilute the essential oils to a level at which they are suitable for use on the skin. Even though aromatherapy carrier oils dilute the scent of the essential oils, the scent can still be quite strong even when there is a high carrier-oil-to-essential-oil ratio. This is because essential oils are incredibly concentrated in their scent. For example, less than ten drops of essential oil are necessary for an entire bathtub full of water for aromatherapy baths.
Every one of the aromatherapy carrier oils has a unique scent. Aromatherapists choose between carrier oils based on the ways in which their natural scents interact with the essential oils with which they will be blended, as well as the aromatherapeutic benefits of the carrier oils themselves. Aromatherapy carrier oils are also chosen based on the ways in which the oil was expressed, the natural nutrients and essential fatty acids that they contain, the way in which they absorb into the skin, and their shelf life. Some aromatherapy buffs also insist on using aromatherapy carrier oils that are extracted from organically grown plants.
Aromatherapy carrier oils that come from nuts are made from such nuts as macadamia nuts, almonds, pecans, and sesame seeds. Those that are made from vegetables are extracted from such fruits and vegetables as avocados, olives, watermelons, apricots, and cranberries. These oils vary greatly in price and availability.