Topical Application of Essential Oils

By Shellie Enteen , RA, BA, LMBT

Topical Application of Essential Oils

By Shellie Enteen , RA, BA, LMBT

When working with essential oils in massage, it's helpful to understand the way they enter the body. Inhalation and the process of olfaction are well-documented and understood. However, the amount and action of essential oils absorbed in topical application is not as understood, nor can it be completely and accurately described at this time.

During inhalation, the volatile molecules of essential oils become a vapor and pass rapidly from the cilia lining in the nasal passage to the olfactory nerve, where they are transported to the olfactory bulb and into the brain. Here, they may enter the limbic region and, reaching the hypothalamus, continue on to either the ANS or the pituitary gland to stimulate hormone activity. Other molecules will pass into the cerebral cortex, stimulating memory, learning and emotional responses. Blood circulation is immediately accessed via the nasal mucosa and the alveoli in the lungs.

Dermal penetration presents a more difficult route, beginning with the fact that percutaneous absorption requires that the essential oil, in liquid form, enters the stratum corneum, the thin outer layer of the skin that is equipped to protect the body from invading organisms. Hair follicles, eccrine and apocrine glands, which account for only 1 percent of the skin's surface, provide easier access than the cells and keratin content of the stratum corneum. Thus, certain areas of the body are said to be more permeable: forehead and scalp, soles and palms, genitals, armpits and mucous membranes.

According to aromatherapist and educator, Salvatore Battaglia, if the essence is able to permeate the complex biological functions of the stratum corneum, a variety of things can occur. One potential is for the essential-oil molecule to remain in the skin itself, where it might be metabolized by cutaneous enzymes. (It is speculated that enzymes might convert some components, such as safrole, methyl-chavicol and carvacrol, into potentially harmful substances.) Another possibility is that the essence remains in the skin, forming a reservoir by binding to the stratum corneum or subcutaneous fat, where it may slowly be released into the capillaries. The best- case scenario is that all or part of the essential oil components will reach, and be completely absorbed into, the cutaneous micro-circulation.

Essential-oil components also might bind with proteins in the skin, which creates the sensitizing response of allergic contact dermatitis. Skin permeability might be increased by:

  • Alteration of the stratum corneum due to cuts, abrasions or thinning of this layer.
  • Hydrating the skin through bathing, sweating or being in a highly humid environment such as a steam room or steam cabinet. Using an aromatherapy massage oil after a hot bath or shower could increase the absorption of essential oils because of stimulated blood flow to the dermis.
  • Using a carrier oil that is more easily absorbed (such as fractionated coconut), as opposed to thicker oils, like olive, that will be absorbed more slowly. Oils rich in polyunsaturated fats are absorbed more easily and certain fatty acids found in cold-pressed vegetable oils also enhance penetration.
  • The use of soap or other surfactants increases permeability. Combine that with the hot shower or bath and an aromatherapy shampoo/shower gel would get a high topical rating.
  • Covering the skin to inhibit evaporation and raise the temperature of the skin - via massage linens, clothing, wraps, masks and other products - also increases hydration of the skin, and circulation to the skin which assists permeability.

Following the idea of increasing circulation for increased permeability, it would seem that the extreme local hyperemia created by massage cupping also would enhance the absorption of whatever essences might be in the carrier oil used for "slip."

Research where the inhalation factor has been completely removed has not yet been accomplished, so these speculations about skin absorption rates have not been clinically proven. None of these studies or speculations takes into account the vibratory action of the essence when it touches the body. These effects can be experienced, if not measured.

Sylla Sheppard-Hanger writes, "Just because whole essential oils may not be absorbed into the bloodstream creating a systemic reaction, beneficial skin effects and certainly the mental effects (relaxation) are very much possible with essential oil treatments. ... Certainly the beneficial mental effects induced when using a pleasing fragrance cannot be denied."

The lack of full dermal penetration might be the very reason why Sylla concludes, "The safest and most pleasant method of delivery is the external use of essential oils (highly diluted), usually in the form of massage."