Aromatherapy and Essential Oils


*Aromatherapy and essential oil facts written by John P. Cunha, DO, FACOEP

  • Aromatherapy is the use of essential oils and plant extracts to promote health and well-being.
  • Aromatherapy is often used in combination with other treatments such as massage therapy or acupuncture.
  • Commonly used essential oils include chamomile, lavender, tea tree, lemon, ginger, and bergamot.
  • The modern use of essential oils for aromatherapy began in the early 20th century and gained popularity in the 1980s as a complementary alternative medicine.
  • Aromatherapy is not used as a treatment for cancer but as supportive care to help manage symptoms of cancer or chemotherapy.
  • Essential oils may be used by direct inhalation, indirect inhalation (such as a diffuser), aromatherapy massage, or applying the oils to the skin in combination with lotions or creams.
  • Some studies have found essential oils have antibacterial effects when applied to the skin. Others may have antiviral or antifungal properties.
  • Clinical trials have been done to study the use of aromatherapy to treat nausea and vomiting caused by chemotherapy and other conditions. Results are mixed. Some studies have shown aromatherapy improved mood, pain, anxiety, nausea, vomiting, and constipation while other studies have shown no effect.

What Is Aromatherapy?

Aromatherapy is the use of essential oils from plants to support and balance the mind, body, and spirit. It is used by patients with cancer mainly as a form of supportive care that may improve quality of life and reduce stress, anxiety, and nausea and vomiting caused by chemotherapy. Aromatherapy may be combined with other complementary treatments like massage therapy and acupuncture, as well as with standard treatments, for symptom management.

Essential oils (also known as volatile oils) are the basic materials of aromatherapy. They represent the fragrant essences found in many plants. These essences are made in special plant cells, often under the surface of leaves, bark, or peel, using energy from the sun and elements from the air, soil, and water. If the plant is crushed, the essence and its unique fragrance are released.

When essences are extracted from plants, they become essential oils. They may be distilled with steam and/or water, or mechanically pressed. Essential oils that are made by processes that modify their chemistry are not considered true essential oils.

There are many essential oils used in aromatherapy, including those from Roman chamomile, geranium, lavender, tea tree, lemon, ginger, cedarwood, and bergamot. Each plant's essential oil has a different chemical composition that affects how it smells, how it is absorbed, and how it is used by the body. Even the essential oils from varieties of the same plant species may have chemical compositions different from each other. The same applies to plants that are grown or harvested in different ways or locations.

Essential oils are very concentrated. For example, it takes about 220 lbs of lavender flowers to make about 1 pound of essential oil. Essential oils are volatile, evaporating quickly when they are exposed to open air.

What Is the History of the Discovery and Use of Aromatherapy as a Complementary and Alternative Treatment for Cancer?

Fragrant plants have been used in healing practices for thousands of years across many cultures, including ancient China, India, and Egypt. Ways to extract essential oils from plants were first discovered during the Middle Ages.

The history of modern aromatherapy began in the early 20th century, when French chemist Rene Gattefosse coined the term aromatherapy and studied the effects of essential oils on many kinds of diseases. In the 1980s and 1990s, aromatherapy was rediscovered in Western countries as interest in complementary and alternative medicine (CAM) began to grow.

What Is the Theory Behind the Claim That Aromatherapy Is Useful in Treating Cancer?

Aromatherapy is rarely suggested as a treatment for cancer, but rather as a form of supportive care to manage symptoms of cancer or side effects of cancer treatment. There are different theories about how aromatherapy and essential oils work. A leading theory is that smell receptors in the nose may respond to the smells of essential oils by sending chemical messages along nerve pathways to the brain's limbic system, which affects moods and emotions. Imaging studies in humans help show the effects of smells on the limbic system and its emotional pathways.

How Is Aromatherapy Administered?

Aromatherapy is used in various ways. Examples include:

  • Indirect inhalation (patient breathes in an essential oil by using a room diffuser or placing drops nearby).
  • Direct inhalation (patient breathes in an essential oil by using an individual inhaler with drops floated on top of hot water) to treat a sinus headache.
  • Aromatherapy massage (massaging of one or more essential oils, diluted in a carrier oil, into the skin).
  • Applying essential oils to the skin by combining them with bath salts, lotions, or dressings.

Aromatherapy is rarely taken by mouth.

There are some essential oils commonly chosen to treat specific conditions. However, the types of oils used and the ways they are combined may vary, depending on the experience and training of the aromatherapist. This lack of standard methods has led to some conflicting research on the effects of aromatherapy.


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Have Any Preclinical (Laboratory or Animal) Studies Been Conducted Using Aromatherapy?

Many studies of essential oils have found that they have antibacterial effects when applied to the skin. Some essential oils have antiviral activity against the herpes simplex virus. Others have antifungal activity against certain vaginal and oropharyngeal fungal infections. In addition, studies in rats have shown that different essential oils can be calming or energizing. When rats were exposed to certain fragrances under stressful conditions, their behavior and immune responses were improved.

One study showed that after essential oils were inhaled, markers of the fragrance compounds were found in the bloodstream, suggesting that aromatherapy affects the body directly like a drug, in addition to indirectly through the central nervous system.

Have Any Clinical Trials (Research Studies With People) of Aromatherapy Been Conducted?

Clinical trials of aromatherapy have mainly studied its use in the treatment of nausea and vomiting caused by chemotherapy, stress, anxiety, and other health-related conditions in seriously ill patients. Several clinical trials of aromatherapy in patients with cancer have been published with mixed results.

A few early studies have shown that aromatherapy may improve quality of life in patients with cancer. Some patients receiving aromatherapy have reported improvement in symptoms such as nausea or pain, and have lower blood pressure, pulse, and respiratory rates. Studies of aromatherapy massage have had mixed results, with some studies reporting improvement in mood, anxiety, pain, and constipation and other studies reporting no effect.

A study of inhaled ginger essential oil in women receiving chemotherapy for breast cancer showed improvements in acute nausea, but no improvement in vomiting or chronic nausea.

A study of inhaled bergamot essential oil in children and adolescents receiving stem cell transplants reported an increase in anxiety and nausea and no effect on pain. Parents receiving the aromatherapy and parents receiving the placebo both showed less anxiety after their children's transplants. In a study of adult patients receiving stem cell transplants, tasting or sniffing sliced oranges was more effective at reducing nausea, retching, and coughing than inhaling an orange essential oil.

A small study of tea tree essential oil as a topical treatment to clear antibiotic -resistant MRSA bacteria from the skin of hospital patients found that it was as effective as the standard treatment. Antibacterial essential oils have been studied to lessen odor in necrotic ulcers.

No studies in scientific or medical literature discuss aromatherapy as a treatment for cancer specifically.

Have Any Side Effects or Risks Been Reported From Aromatherapy?

Safety testing on essential oils shows very few side effects or risks when they are used as directed. Some essential oils have been approved as ingredients in food and are classified as GRAS (generally recognized as safe) by the U.S. Food and Drug Administration, within specific limits. Swallowing large amounts of essential oils is not recommended.

Allergic reactions and skin irritation may occur in aromatherapists or in patients, especially when essential oils are in contact with the skin for long periods of time. Sun sensitivity may develop when citrus or other essential oils are applied to the skin before sun exposure.

Lavender and tea tree essential oils have been found to have some hormone-like effects. They have effects similar to estrogen (female sex hormone) and also block or decrease the effect of androgens (male sex hormones). Applying lavender and tea tree essential oils to the skin over a long period of time has been linked in one study to breast enlargement in boys who have not yet reached puberty. It is recommended that patients with tumors that need estrogen to grow avoid using lavender and tea tree essential oils.

Is Aromatherapy Approved by the U.S. Food and Drug Administration (FDA) for Use as a Cancer Treatment in the United States?

Aromatherapy products do not need approval by the Food and Drug Administration because no specific claims are made for the treatment of cancer or other diseases.

Aromatherapy is not regulated by state law, and there is no licensing required to practice aromatherapy in the United States. Professionals often combine aromatherapy training with another field in which they are licensed, for example, massage therapy, registered nursing, acupuncture, or naturopathy. Some aromatherapy courses for healthcare providers offer medical credit hours and include conducting research and measuring results.

The National Association for Holistic Aromatherapy ( and the Alliance of International Aromatherapists ( are two organizations that have national educational standards for aromatherapists. The National Association for Holistic Aromatherapy (NAHA) plans to have a standard aromatherapy certification in the United States. There are many schools that offer certificate programs approved by NAHA. A list of these schools can be found at National exams in aromatherapy are held twice a year.

The Canadian Federation of Aromatherapists ( certifies aromatherapists in Canada. See the International Federation of Aromatherapists website ( for a list of international aromatherapy programs.

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United States. National Cancer Institute. "Aromatherapy and Essential Oils (PDQ®) -- Patient Version." June 9, 2017. <>.

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