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Complementary & Alternative Medicine
Index Of Alternative Therapies And Modalities
When deciding to begin a complementary therapy or to see a complementary practitioner, first speak with your primary health care provider.
Before engaging in any complementary medical technique, you should be aware that many of these techniques have not been evaluated in scientific studies. Often, only limited information is available about their safety and effectiveness. Each state and each discipline has its own rules about whether practitioners are required to be professionally licensed. If you plan to visit a practitioner, it is recommended that you choose one who is licensed by a recognized national organization and who abides by the organization's standards. It is always best to speak with your primary health care provider before starting any new therapeutic technique.
For thousands of years, oils from plants have been used to lubricate the skin, purify air and repel insects. Essential oils were used in ancient Egypt for bathing and massage and in ancient Greece and Rome for treating infections. The origin of modern aromatherapy is often traced to the French chemist Rene-Maurice Gattefosse, who is said to have poured lavender oil onto his hand after accidentally burning himself. He believed that the pain, redness and skin damage healed more quickly than expected, and he began to study the effects of oils on the body.
Essential oils are extracted from a plant's flowers, leaves, needles, branches, bark, berries, seeds, fruits, rind or roots. These oils are often mixed with a milder "carrier" oil (usually a vegetable oil) or are weakened (diluted) in alcohol. Essential oils are used in many different ways, including directly on the skin, as a part of massage, in bathwater, via steam inhalation or in mouthwashes.
Aromatherapy sessions often begin with an interview, after which the therapist selects a blend of oils that he or she feels is appropriate for the client. Appointments may last up to 90 minutes. Clients may be asked not to shower for several hours afterwards, to allow more time for oils to sink into the skin. Manmade compounds are usually not used. Commonly sold products such as scented candles, pomanders or potpourri are usually not as strong as the oils typically used by aromatherapists.
There is no required training or licensing for aromatherapists in the United States. Many types of practitioners, including massage therapists, chiropractors and nurses, offer aromatherapy.
Different theories have been proposed to explain the reported effects of aromatherapy, although none has been proven scientifically. Some explanations include:
- Stimulation of pleasure centers of the brain by nerves in the nose that sense smell
- Direct effects on hormones or enzymes in the blood
- Stimulation of the adrenal glands
Scientists have studied aromatherapy for the following health problems:
Lavender aromatherapy is traditionally believed to be relaxing. Several small studies report that it helps relieve anxiety. Overall, the scientific evidence suggests a small benefit. It is possible that aromatherapy may have effects on mood, cognitive performance and relaxation in adults. Larger, well-designed studies are needed to confirm the available data.
Agitation in patients with dementia
There is early evidence that aromatherapy using essential oil of lemon balm (Melissa officinalis) can effectively reduce agitation in people with severe dementia when applied to the face and arms twice daily. Other research reports that steam inhalation of lavender aromatherapy may have similar effects. However, other research reports no benefits of aromatherapy using lemon balm, Lavender officinalis, sweet orange (Citrus aurantium), or tea tree oil (Malaleuca alternifolia). Overall, the evidence does suggest potential benefits. There is also early research suggesting that aromatherapy used with massage may help to calm people with dementia who are agitated. However, it is not clear if this approach is any better than massage used alone. Additional research is necessary before strong recommendations can be made.
Poor sleep, sedation
Lavender and chamomile are popularly regarded as effective sleep aids. Research is too early to form a clear conclusion.
Quality of life in patients with cancer or life-threatening illnesses
Aromatherapy and aromatherapy massage are often used in people with severe illnesses to improve quality of life. However, currently there is not enough scientific evidence to form a firm conclusion about effectiveness.
Alopecia areata (hair loss)
Alopecia areata is a condition in which the body's immune system attacks hair follicles, causing hair loss. A well-designed study using a mixture of oils (cedarwood, lavender, rosemary and thyme in carrier oils of grapeseed and jojoba) reported improvements in patients compared with patients using carrier oils alone. More research is needed before a clear conclusion can be reached.
Congestion, respiratory tract infection
Eucalyptus oil and a component of eucalyptus called eucalyptol are included in many over-the-counter vapors and other treatments. However, there is not enough scientific information to form a clear conclusion at this time.
Itching in dialysis patients
It is not clear if aromatherapy reduces itchiness in patients with kidney disease on dialysis.
Anxiety or stress in intensive care unit patients
It is not clear if aromatherapy reduces stress levels in patients in intensive care units. Early research suggests that it may not be helpful.
A small trial of aromatherapy for pain management in women during labor gave unclear results. More research is needed to make a conclusion.
Aromatherapy may play a role in reducing postoperative nausea. However, the evidence is not clear, and more research is needed before a clear recommendation can be made.
It has been suggested that aromatherapy massage may reduce abdominal obesity or appetite. Additional evidence is necessary before a clear conclusion can be reached.
Preliminary research in this area is inconclusive.
One study comparing aromatherapy to acupuncture for their effects on alcohol withdrawal symptoms did not find a difference between the treatments.
Early research in arthritis patients using aromatherapy yielded unclear results. More research is needed in this area.
Atopic eczema (pediatric)
Early data is unclear as to whether or to what extent aromatherapy might benefit children with atopic eczema. More studies are needed before recommendations can be made.
Chronic obstructive pulmonary disease (COPD)
Early evidence from one small trial suggests aromatherapy may aid mucus clearance in COPD. More studies are needed before conclusions about this application of aromatherapy can be made.
Early clinical research has been conducted in patients with mild depression using aromatherapy massage. More research is needed in this area.
In a clinical trial using abdominal aromatherapy massage with a combination of essential oils, menstrual cramps were reduced. More research is needed in this area to identify which oil may cause benefit.
In a clinical trial, massage and skin care with and without aromatherapy improved relief and well-being in breast cancer patients. However, there was no noticeable difference between aromatherapy massage group and the massage-alone group.
Aromatherapy is popularly used to improve mood. An early study found that first-time mothers had improved mood after aromatherapy. Higher-quality research is needed in this area.
Early clinical research reports unclear results. More research is needed that studies aromatherapy as a monotherapy for stroke recovery.
Early data from one small study suggests aromatherapy may contribute to reduced pain intensity during dressing changes in wound care. Further research is needed before a recommendation can be made.
Aromatherapy has been suggested for many other uses, based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially life-threatening. Consult with a health care provider before using aromatherapy for any use.
Bereavement and grief
Chronic bronchitis (prevention and treatment)
Cognitive performance enhancement
Enhanced recovery from surgery or illness
Guillain-Barré syndrome (symptom relief)
High blood pressure
Hormonal and endocrine disorders
Immune system stimulant
Inflammatory bowel disease
| Intravenous line infection|
Loss of appetite
Reduced swelling after injuries
Respiratory tract infections (prevention)
Sexually transmitted diseases
Sickle cell disease
Skin rash in bone marrow transplant patients (engraftment syndrome rash)
Smoking withdrawal symptoms
Sprains and strains
Stimulation of digestion
Study performance (math tasks)
Essential oils may be toxic if taken by mouth and should not be swallowed.
Many types of essential oils can cause skin rash or irritation on direct contact, and they should be diluted with a base oil before use. Some oils, such as peppermint and eucalyptus oils, may burn the skin if applied at full strength. Skin sensitivity to light may occur, particularly with oil of bergamot (extracted from the rind of the bergamot orange) or a chemical in oil of bergamot called 5-methoxypsoralen. Vapors released during aromatherapy can irritate the eyes. Use near children's faces is discouraged.
Allergy may occur with use of essential oils; it may be caused by contamination or by constituents of the herbs from which the oil is derived. Individuals who have difficulty breathing with the use of aromatherapy should seek medical attention before attempting aromatherapy again.
There are published reports of agitation, drowsiness, nausea and headache with the use of aromatherapy. Some oils are thought to have toxic effects on the brain, liver and kidney or to increase the risk of cancer with long-term use. Aromatherapies that may increase sedation or drowsiness, such as lavender or chamomile, may enhance the effects of drugs, herbs or supplements that also cause fatigue or sedation. Use caution if you are driving or operating heavy machinery.
Sage, rosemary and juniper oils may cause the uterus to contract when taken in large amounts, and their use is discouraged during pregnancy.
Infants and young children may be especially sensitive to the effects and side effects of essential oils. Peppermint oil is not recommended in children younger than 30 months. Consult a health care provider before using aromatherapy in children.
Fragrances may contain unknown and potentially toxic contaminants. There are reports that lead emission may occur from the burning wick of aromatherapy candles, although long-term health effects are not clear.
Essential oils may interact with drugs, herbs, foods, and/or labs in various ways depending on the specific combination. There is a lack of research on interaction effects of specific combinations.
Aromatherapy has been suggested for many health conditions. Several small studies suggest that lavender aromatherapy may help relieve anxiety. There is no conclusive scientific evidence for the effectiveness of any other use or type of aromatherapy. Essential oils may be toxic if taken by mouth and should not be swallowed. Several other adverse effects have been reported, most commonly skin allergy or irritation after direct contact. Some types of aromatherapy may be dangerous in children and in pregnant women. Do not rely on aromatherapy alone to treat potentially dangerous medical conditions. Speak with your health care provider if you are considering the use of aromatherapy.
The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.
- Natural Standard: An organization that produces scientifically based reviews of complementary and alternative medicine (CAM) topics
- National Center for Complementary and Alternative Medicine (NCCAM): A division of the U.S. Department of Health & Human Services dedicated to research
Selected Scientific Studies: Aromatherapy
Natural Standard has reviewed all of the currently available medical literature to prepare the professional monograph from which this version was created.
Some of the more recent studies are listed below:
- Anderson LA, Gross JB. Aromatherapy with peppermint, isopropyl alcohol, or placebo is equally effective in relieving postoperative nausea. J Perianesth Nurs 2004;19(1):29-35.
- Burnett KM, Solterbeck LA, Strapp CM. Scent and mood state following an anxiety-provoking task. Psychol Rep 2004;95(2):707-722.
- Burns E, Zobbi V, Panzeri D, et al. Aromatherapy in childbirth: a pilot randomised controlled trial. BJOG 2007;Jul, 114(7):838-844.
- 4Calvert I. Ginger: an essential oil for shortening labour? Pract Midwife 2005;8(1):30-34.
- Fellowes D, Barnes K, Wilkinson S. Aromatherapy and massage for symptom relief in patients with cancer. Cochrane Database Syst Rev 2004;CD002287.
- Gedney JJ, Glover TL, Fillingim RB. Sensory and affective pain discrimination after inhalation of essential oils. Psychosom Med 2004;66(4):599-606.
- Han SH, Hur MH, Buckle J, et al. Effect of aromatherapy on symptoms of dysmenorrhea in college students: a randomized placebo-controlled clinical trial. J Altern Complement Med 2006;Jul-Aug, 12(6):535-541.
- Kim MA, Sakong JK, Kim EJ, et al. [Effect of aromatherapy massage for the relief of constipation in the elderly]. Taehan Kanho Hakhoe Chi 2005;35(1):56-64.
- Muzzarelli L, Force M, Sebold M. Aromatherapy and reducing preprocedural anxiety: a controlled prospective study. Gastroenterol Nurs 2006;Nov-Dec, 29(6):466-471.
- Natural Standard Research Collaboration, Chief Editors: Ulbricht C, Basch E, Natural Standard Herb and Supplement Reference. Evidence-Based Clinical Reviews, USA. Elsevier/Mosby, 2005.
- Okamoto A, Kuriyama H, Watanabe S, et al. The effect of aromatherapy massage on mild depression: a pilot study. Psychiatry Clin Neurosci. 2005 Jun;59(3):363.
- Soden K, Vincent K, Craske S, et al. A randomized controlled trial of aromatherapy massage in a hospice setting. Palliat Med 2004;18(2):87-92.
- Wilkinson SM, Love SB, Westcombe AM, et al. Effectiveness of aromatherapy massage in the management of anxiety and depression in patients with cancer: a multicenter randomized controlled trial. J Clin Oncol 2007;Feb 10, 25(5):532-539.
Last updated April 29, 2008
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