From Chapter 16 of The 6th Edition Essential Oils Desk Reference, for complete information, see the link at the end of the article.
The process of emotional release using essential oils should not be dramatic, but gentle, occurring step-by-step over a period of time. Application of the oils accompanied by mental focus and relaxation should occur multiple times per day. Some emotional blocks will require only a day or two to begin releasing; others may require weeks.
Another way in which essential oils can assist in helping people to move beyond emotional blocks is through their relaxing effect. The aldehydes and esters of certain essential oils such as Lavender, Ruta, Frankincense, etc., are very calming and sedating to the nervous system (including both the sympathetic and parasympathetic systems). These substances allow us to relax instead of getting caught in an anxiety spiral.
Anxiety creates an acidic condition that activates the transcript enzyme, which then transcribes that anxiety on the RNA template and stores it in the DNA. That emotion then becomes a predominant factor in our lives from that moment on.
Many people find essential oils have a calming and relaxing effect when used to help focus and release negative emotions. Here are some oils from the 6th Edition Essential Oil Desk Reference* that help with Fear and Frustration:
Palo Santo, Cypress, Geranium, Juniper, Spruce, Tangerine, Cedarwood, Roman Chamomile, Rosemary, Copaiba, Thyme, Lemon, Lavender
*Excerpts taken from page 418 and 423 of The 6th Edition Essential Oils Desk Reference, for a complete list of oils and emotions see Chapter 16, Spiritual, Mental, and Emotional Support with Essential Oils.