Basil is a top note, and can often times overpower other essential oils when creating blends or synergies.
Aromatically, Basil essential oil is typically sweet, herbaceous, and slightly campherous. At times, you will detect a slight hint of fennel or black licorice aroma. This aroma will of course vary depending upon the type of essential oil you purchase and where it was grown and harvested.
For instance, Basil essential oils that are higher in Linalool will often times offer a more appealing aroma.
The key differentiator, and identifier, continues to be found in the Latin name of the particular essential oil you purchase.
Common And Not So Common “Basil Essential Oil” 
Basil essential oil is primarily composed of Monoterpenols (52%), Sesquiterpenes (20%), and Oxides (7.2%).
Monoterpenols: Essential oils containing monoterpenols tend to be excellent for supporting the skin as well as offering some calming and soothing benefits.
Sesquiterpenes: This chemical family is more difficult to generalize, and is largely considered a wild card. Many essential oils high in Sesquiterpenes are known for their cleansing, clearing, and calming properties. They are also said to promote general healing.
Oxides: When Oxides are present, you should immediately think 1, 8 cineole. They are generally supportive of healthy respirations and also support healthy brain function and clarity.
Basil essential oil offers a tremendous variety of therapeutic, emotional, and spiritual benefits (some even surprising). It is probably most popular for helping to main and support muscle activity and healthy joints. It may occasionally support digestive activity, stimulate and support a healthy immune system, and support the skin. Surprisingly enough, Basil essential oil is popular for promoting focus and mental acuity.
Basil essential oil should be used cautiously depending upon the exact species of essential oil you are using. Basil (estragole CT) can be potentially carcinogenic along with other varieties containing estragole. Sacred Basil (aka, tulsi / Ocimum tenuiflorum L) may interact with specific medications, can inhibit blood clotting, and may irritate the skin and mucous membranes.
As such, and with all essential oils, you should avoid neat application to the skin and be familiar with what specific Basil essential oil you have and are using.
Basil is listed as having GRAS status. However, it is extremely important to note that Basil as a food additive and seasoning is what qualifies this plant with GRAS status.
We do NOT recommend or support the internal use of Basil essential oil for therapeutic purposes. We also recommend you avoid using this potent and pure essential oil as a food additive or substitute for the seasoning.
NOTE: Essential oils should NOT be taken internally at all unless you are under the care of a qualified professional or have been thoroughly trained yourself.
Basil essential oil has been referred to as “the royal oil to strength the mind and heart. There is repeated evidence throughout history demonstrating Basil being relied on and used to clear the mind and soothe the soul.
Blends Well With…
Basil essential oil can be a strong aroma and it has been suggested that any blending or synergy creation should delicately include this particular oil until you become more familiar with how it expresses itself.
You may enjoy blending Basil essential oil with Bergamot, Black Pepper, Cedarwood, Cypress, Fennel, Geranium, Grapefruit, Helichrysum, Lavender, Lemon, Lemongrass, Marjoram, Peppermint, White Fir, and Wintergreen essential oils.