Most people tend to associate aromatherapy with scented essential oils like lavender, eucalyptus or grapefruit. However, base oils are just as "essential" to the practice, used to dilute potent oils that would otherwise irritate sensitive skin.
Concentrated essential oils can cause itching, burning and redness when applied to unprotected skin. Neutral, mostly fragrance-free base oils reduce the intensity of essential oils without compromising their healing properties.
Also known as "carrier" oils, base oils are typically cold-pressed from the seeds, nuts, and leaves of plants. The most popular include olive, jojoba, safflower, coconut and almond oils.
As the foundation for many commercial aromatherapy blends and massage oils, base oils provide a cost-effective way to cover a large area of skin with a relatively small amount of essential oil. Common oils like olive or canola can be found in grocery stores; check health food stores or on-line vendors for more exotic varieties.
Standard homemade aromatherapy blends combine up to ten drops of essential oil per 20 milliliters of base oil. The ratio of essential oil to base oil varies depending on the oils involved.
Adverse reactions to base oils are atypical. Those with nut allergies should avoid nut-based carrier oils, including peanut, walnut, almond and hazelnut.