Home > Patients & Visitors > Health Library > Aromatherapy and Essential Oils (PDQ®): Integrative, alternative, and complementary therapies - Patient Information [NCI]
This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http://cancer.gov or call 1-800-4-CANCER.
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.
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.
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.
Aromatherapy is used in various ways. Examples include:
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.
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.
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.
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.
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 (www.naha.org) and the Alliance of International Aromatherapists (www.alliance-aromatherapists.org) 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 http://www.naha.org/schools_level_one_two.htm. National exams in aromatherapy are held twice a year.
The Canadian Federation of Aromatherapists (www.cfacanada.com) certifies aromatherapists in Canada. See the International Federation of Aromatherapists website (www.ifaroma.org/) for a list of international aromatherapy programs.
Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.
Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.
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Purpose of This Summary
This PDQ cancer information summary has current information about the use of aromatherapy and essential oils in the treatment of people with cancer. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.
Reviewers and Updates
Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.
The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Integrative, Alternative, and Complementary Therapies Editorial Board.
Clinical Trial Information
A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Clinical trials are listed in PDQ and can be found online at NCI's website. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).
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The best way to cite this PDQ summary is:
PDQ® Integrative, Alternative, and Complementary Therapies Editorial Board. PDQ Aromatherapy and Essential Oils. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/about-cancer/treatment/cam/patient/aromatherapy-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389261]
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Complementary and alternative medicine (CAM)-also called integrative medicine-includes a broad range of healing philosophies, approaches, and therapies. A therapy is generally called complementary when it is used in addition to conventional treatments; it is often called alternative when it is used instead of conventional treatment. (Conventional treatments are those that are widely accepted and practiced by the mainstream medical community.) Depending on how they are used, some therapies can be considered either complementary or alternative. Complementary and alternative therapies are used in an effort to prevent illness, reduce stress, prevent or reduce side effects and symptoms, or control or cure disease.
Unlike conventional treatments for cancer, complementary and alternative therapies are often not covered by insurance companies. Patients should check with their insurance provider to find out about coverage for complementary and alternative therapies.
Cancer patients considering complementary and alternative therapies should discuss this decision with their doctor, nurse, or pharmacist as they would any type of treatment. Some complementary and alternative therapies may affect their standard treatment or may be harmful when used with conventional treatment.
It is important that the same scientific methods used to test conventional therapies are used to test CAM therapies. The National Cancer Institute and the National Center for Complementary and Integrative Health (NCCIH) are sponsoring a number of clinical trials (research studies) at medical centers to test CAM therapies for use in cancer.
Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Few CAM therapies have been tested using demanding scientific methods. A small number of CAM therapies that were thought to be purely alternative approaches are now being used in cancer treatment-not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health (NIH) meeting in November 1997, acupuncture has been found to help control nausea and vomiting caused by chemotherapy and pain related to surgery. However, some approaches, such as the use of laetrile, have been studied and found not to work and to possibly cause harm.
The NCI Best Case Series Program which was started in 1991, is one way CAM approaches that are being used in practice are being studied. The program is overseen by the NCI's Office of Cancer Complementary and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients' medical records and related materials to OCCAM. OCCAM carefully reviews these materials to see if any seem worth further research.
When considering complementary and alternative therapies, patients should ask their health care provider the following questions:
National Center for Complementary and Integrative Health (NCCIH)
The National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health (NIH) facilitates research and evaluation of complementary and alternative practices, and provides information about a variety of approaches to health professionals and the public.
CAM on PubMed
NCCIH and the NIH National Library of Medicine (NLM) jointly developed CAM on PubMed, a free and easy-to-use search tool for finding CAM-related journal citations. As a subset of the NLM's PubMed bibliographic database, CAM on PubMed features more than 230,000 references and abstracts for CAM-related articles from scientific journals. This database also provides links to the websites of over 1,800 journals, allowing users to view full-text articles. (A subscription or other fee may be required to access full-text articles.)
Office of Cancer Complementary and Alternative Medicine
The NCI Office of Cancer Complementary and Alternative Medicine (OCCAM) coordinates the activities of the NCI in the area of complementary and alternative medicine (CAM). OCCAM supports CAM cancer research and provides information about cancer-related CAM to health providers and the general public via the NCI website.
National Cancer Institute (NCI) Cancer Information Service
U.S. residents may call the NCI Cancer Information Service toll free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 am to 8:00 pm. A trained Cancer Information Specialist is available to answer your questions.
Food and Drug Administration
The Food and Drug Administration (FDA) regulates drugs and medical devices to ensure that they are safe and effective.
Federal Trade Commission
The Federal Trade Commission (FTC) enforces consumer protection laws. Publications available from the FTC include:
Last Revised: 2017-06-09
If you want to know more about cancer and how it is treated, or if you wish to know about clinical trials for your type of cancer, you can call the NCI's Cancer Information Service at 1-800-422-6237, toll free. A trained information specialist can talk with you and answer your questions.
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