What are Carrier Oils?

Shown is a variety of cold pressed vegetable oils ranging in color from clear Fractionated Coconut Oil to dark Avocado Oil.  

A carrier oil is a vegetable oil derived from the fatty portion of a plant, usually from the seeds, kernels or the nuts.

If applied to the skin undiluted, essential oils, absolutes, CO2s and other concentrated aromatics can cause severe irritation or reactions in some individuals. Carrier oils are used to dilute essential and other oils prior to application. They carry the essential oil onto the skin.

Each carrier oil offers a different combination of therapeutic properties and characteristics. The choice of carrier oil can depend on the therapeutic benefit being sought.

Natural lotions, creams, body oils, bath oils, lip balms and other moisturizing skin care products are also made using vegetable (carrier) oils. From a simple essential oil/carrier oil blend to a more complex natural lotion, your choice of carrier oil can make a difference in the therapeutic properties, color, overall aroma and shelf life of your final product.

Adding essential oil, drop by drop, to a tablespoon of carrier oil.  

Essential vs. Carrier Oils

Essential oils are distilled from the leaves, bark, roots and other aromatic portions of a botanical. Essential oils evaporate and have a concentrated aroma. Carrier oils, on the other hand, are pressed from the fatty portions (seeds, nuts, kernels) and do not evaporate or impart their aroma as strongly as essential oils. Carrier oils can go rancid over time, but essential oils do not. Instead, essential oils "oxidize" and lose their therapeutic benefits, but they don't go rancid.

Vegetable Oils/Fixed Oils/Base Oils

The term carrier oil is generally limited to use within the practice of aromatherapy. In natural skin care, carrier oils are typically referred to as vegetable oils, fixed oils or base oils. Not all fixed oils/base oils are vegetable oils. Emu oil (from the emu bird) and fish (marine) oils are also classified as fixed/base oils, but these animal-based oils are generally not used for aromatherapy work.

The Aroma of Carrier Oils

Some carrier oils are odorless, but generally speaking, most have a faintly sweet, nutty aroma. If you come across a carrier oil that has a strong, bitter aroma, the carrier oil may have gone rancid. See the Carrier Oils and Rancidity section of this article for information on rancidity.

Examples of vegetable oils that are used as a carrier in aromatherapy:

Sweet Almond Oil     Kukui Nut Oil

Apricot Kernel Oil   Macadamia Nut Oil

Avocado Oil   Meadowfoam Oil

Borage Seed Oil   Olive Oil

Camellia Seed Oil (Tea Oil)   Peanut Oil

Cranberry Seed Oil   Pecan Oil

Evening Primrose Oil   Pomegranate Seed Oil

Fractionated Coconut Oil   Rose Hip Oil

Grapeseed Oil   Seabuckthorn Berry Oil

Hazelnut Oil   Sesame Oil

Hemp Seed Oil   Sunflower Oil

Jojoba   Watermelon Seed Oil

Shopping For Carrier Oils

Trends are changing, but most typical vegetable oils sold in grocery stores are not cold-pressed. Instead, the oils are processed using heat. For the most nourishing, freshest carrier oils, strive to shop with retailers and suppliers that specialize in the sale of aromatherapy or natural skin care ingredients. Your local health food/nutrition store may be a source for carrier oils, but the oils can often be pricier. Watch for dust on the bottles when buying oils locally. That can indicate the oil has been sitting around for awhile. Look for oils that are not blends of two or more oils and that have no additives.

Processing Method: Shop for carrier oils that have been cold pressed or cold expeller pressed. This indicates that the oil has been pressed from the fatty portions of the botanical without the use of added heat. The process can still generate heat due to the friction of the method, but cold expeller pressed oils are processed under conditions that keep the heat to a minimum. Oils that simply say expeller pressed have not been processed to maintain low heat levels. When oils are processed without cool conditions, the high temperature degree and duration of the processing method can harm the fragile nutrients in the oil.

Nutrients: Carrier oils can contain fat soluble vitamins, minerals and other nutrients. Seabuckthorn Berry Oil, for instance, has such a high ratio of beta carotene that the oil is orange and is amongst the most vivid of oils. Oils that naturally contain tocopherols (Vitamin E) act as anti-oxidants which are both helpful to the skin and generally help extend the shelf life of the oil.

Essential Fatty Acids: Essential Fatty Acids are fatty acids that our bodies cannot manufacture and need to get from our diets. When applied topically, they are very nourishing to our skin. Carrier oils vary in their ratio and specific EFAs that they contain. EFAs are a benefit to the skin, but they also can make an oil more fragile and prone to quicker rancidity. See the Essential Fatty Acids article for more information.

Price: Carrier oils can vary greatly in price based on several factors: The botanical it's made from, how it was processed, if it's organic, the quantity that you're purchasing, and the source that you're purchasing it from.

Organic: Organic carrier oils generally cost more than conventional oils. When purchasing organic carrier oils, verify if the oil is certified.

Color: Color doesn't always matter when selecting a carrier oil for simple blends, but it can matter if you are making more elaborate recipes where the color of your final product is important to you.

Aroma: The aroma of some carrier oils can compete or conflict with the aroma of the essential oils in your desired blend.

Viscosity: Viscosity is a measurement of the resistance of a liquid to movement and flow. For our purposes in comparing carrier oils, I keep things simple by defining them as having a "thin," "medium" or "thick" viscosity.

Absorption/Feel: This is a rather subjective evaluation of how thoroughly and quickly an oil penetrates the skin, and if it makes the skin feel oily after application.

Shelf Life: Carrier oils vary in how long they last before oxidizing and becoming rancid. When purchasing carrier oils, estimate the quantity of oil that you think you'll use within the lifetime of the oil. See the Carrier Oils and Rancidity section of this article for information on shelf life and rancidity.

AromaWeb's Business Plaza provides a helpful categorical directory of sellers of Carrier Oils and other aromatherapy products.

Avoid Mineral Oil

Mineral oil and petrolium jelly are byproducts of petrolium production and are not used in aromatherapy. Mineral oil is used in baby oils and many commercially available moisturizers because it is an inexpensive oil to manufacture. It, however, can clog pores, prevent the skin from breathing naturally, prevent essential oil absorption, prevent toxins from leaving the body through the natural process of sweating, and I've read reports that it can be absorbed into the body and block vitamins from properly being utilized. These same concerns apply to petrolium jelly.

Storing Carrier Oils

For fragile carrier oils or for those that you will be keeping for a long duration, store them in dark glass bottles with tight fitting tops, and store them in a cool, dark location. Amber or cobalt Boston round bottles are ideal.

If you will will be using up an oil well before its lifespan, it really doesn't need to be transfered to dark glass. When you purchase carrier oils, the supplier may have packaged it in a plastic (PET/HDPE) bottle. This doesn't mean that the oil is inferior. Often suppliers use plastic bottles to save packaging and shipping costs and because many customers use up the oils shortly after purchase. Unlike with essential oils which should always be stored in glass (essential oils can dissolve the plastic), carrier oils can be stored in plastic.

Most carrier oils can be stored in the refrigerator, and this can help prolong the lifespan of fragile oils like Borage Seed Oil. Avocado Oil, however, should not be stored in the refrigerator. Oils stored in the refrigerator may solidify or turn cloudy and will need time to return to room temperature prior to use.

Carrier Oils and Rancidity

Essential oils do not go rancid. Carrier oils, however, do become rancid over time. The level of natural fatty acids, tocopherols, method of extraction and other characteristics of an oil all can affect how quickly an oil becomes rancid. If you come across a carrier oil that has a strong, bitter aroma, the carrier oil may have gone rancid. If you can, compare the aroma of the oil that you suspect is rancid with the same botanical oil that you know is fresh.

Carrier oils that you purchase should be natural and unadulterated. Exceptions include buying carrier oils that have natural Vitamin E added. Vitamin E, often listed as tocopherols acts as a natural preservative.

Vegetable Butters and Other Ingredients As Carriers

Vegetable buttes are not carrier oils, but the beneficial properties of vegetable butters like Cocoa Butter and Shea Butter make them lipids that are suitable for use in aromatherapy.

Vegetable butters are similar to vegetable oils but are solid at room temperature. Vegetable butters are processed by a wide variety of methods, so it's especially important to check the method of extraction when shopping for butters. Strive to use butters that are cold pressed.