March 22, 2017



Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • Attunement, biofield therapies, distant healing, energy healing, energy medicine, external qigong, group healing, healing touch, Karuna ReikiTM, ki, laying on of hands, Medicine Buddha, meditation, pranic healing, qigong, Reiki touch therapy, self healing, spiritual healing, Tara Reiki, Tera Mai ReikiTM, therapeutic touch, traditional Japanese Reiki, touch therapies, universal life energy, Usui system, Western Reiki.


  • Reiki is an ancient healing practice that is approximately 2,500 years old. The name "Reiki" is derived from two Japanese words: rei meaning universal spirit and ki meaning life energy. Mention of Reiki can be found in the Tibetan sutras and in ancient records of cosmology and philosophy.

  • Hichau Mikao Usui, a Japanese physician and Buddhist monk, revitalized the practice of Reiki in the 19th Century. It is said that after 21 days of fasting, Reiki was presented to Usui on Mt. Kurama, a Japanese mountaintop near Kyoto during a spiritual experience. By this account, light struck him upon the forehead opening up a "third eye" possessing the highest source of power in the human body. Usui passed down his teachings, and Hawayo Tokata, a Japanese Hawaiian, introduced Usui Reiki to the West in 1930.

  • In modern times, multiple styles and historical accounts of Reiki are taught and practiced. In general, there are three levels of certifications/attunements associated with the practice of Reiki. A Level I degree often involves a weekend course that teaches the potential practitioner to transfer "universal life energy" to him/herself and to others. Students are trained in the concepts and hand positions of Reiki. Four ceremonies (attunements) are performed with the goal of opening students' inner healing channels to engage them in the flow of energy. The Level II degree includes an initiation ceremony that aims to enhance the practitioner's ability to interact with the flow of energy. Other training may include distant healing, teaching of symbols, and enhancement of mental/emotional/spiritual healing. In some cases, practitioners receive a Level II degree after 'intuitively' receiving Sanskrit symbols from spirit guides that are believed to increase their healing powers. The Reiki Master degree (Level III) takes years of close training with a Reiki Master and allows the practitioner to teach Reiki to others.

  • Reiki practitioners conduct sessions with the intention to heal specific maladies or to improve overall well-being. Treatments involve the systematic placing of hands in 12 to 15 varying positions. Hand positions are held for approximately 2-5 minutes each. Hands may be placed directly on a clothed patient or held one to two inches above the skin. The practitioner's hands are positioned palm-side down with the fingers and thumb extended. The standard positions may be modified if deemed necessary by the practitioner. The timing of the hand positions may be cut short if the practitioner believes that he or she senses energy flow. All of the body systems can be covered with the hand positions within 30 to 90 minutes. The number of sessions varies from patient to patient based on the judgment of the practitioner. Acute issues may be treated faster than chronic conditions.

  • Patients have reported feeling different sensations during Reiki sessions such as warmth, tingling, sleepiness, relaxation, or invigoration. Practitioners have reported tingling in their fingers, heat, cold, or pulsing while administering Reiki.

  • Sometimes a technique called "sweeping" is used prior to starting the formal healing session. Sweeping involves the practitioner aiming to pass hands through the patient's energy field. This technique is said to allow the practitioner to more easily detect areas of energy disruption, imbalance, or blockage and to cleanse patients of negative feelings, emotions, or physical burdens.

  • Principles taught in Reiki include: "just for today do not worry," "just for today do not be angry," "just for today give thanks for your many blessings," "honor your parents, teachers and elders," "earn your living honestly," "be kind to your neighbors and every living thing," and "show gratitude to everything."

  • Types of related therapies include distant healing, self-healing, group healing, Tera Mai ReikiTM, Karuna ReikiTM, traditional Japanese Reiki, Tara Reiki, and Western Reiki. There are numerous schools and professional Reiki organizations. The International Association of Reiki Professionals maintains a list of practitioners who have pledged to uphold a Code of Ethics developed by the group.

  • Reiki is also used on animals, including horses. Reiki Masters believe that all living beings are affected by the "universal life energy" flow around them, and animals may be treated in the same manner as humans.


  • Reiki practitioners believe that therapeutic effects of this technique are obtained from a "universal life energy" that provides strength, harmony, and balance to the body and mind. Life energy is thought to be transferred to patients when practitioners place their hands on or directly above treatment areas. This life energy is thought to vitalize organs and cells and to release trapped negative energy. Practitioners do not view themselves as the sources of life energy.

  • Reiki practitioners believe that human energy flows through meridians (or pathways) in the body that can be sensed by trained individuals. A disturbance in the flow of this energy may be caused by physical illnesses or negative emotions. Reiki practitioners aim to channel life energy to problem areas where the patient's energy flow is sensed as being disrupted.

  • Practitioners believe that Reiki can treat symptoms and enable patients to feel enlightened with improved mental clarity, well-being, and spirituality. Reiki is sometimes administered to patients who are dying with the goal of instilling a sense of peace.

  • It has been proposed that Reiki can lower heart rate and blood pressure, boost the immune system and endocrine (hormonal) systems, stimulate endorphins, or affect skin temperature and blood hemoglobin levels. However, these properties have not been well-studied or clearly demonstrated in scientific studies.

  • Reiki has been used or suggested for the management of many conditions. However, Reiki is not well studied scientifically. There are several challenges to conducting high quality research on techniques such as Reiki: there are different styles of practice with variation from practitioner to practitioner; it is challenging to design studies with "placebo" Reiki; and there is no widespread agreement on how best to measure outcomes. Better research is needed before a recommendation can be made either for or against the effectiveness of Reiki for any specific condition.

Scientific Evidence


These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.


Autonomic nervous system disturbances

One randomized trial suggested that Reiki may have an effect on autonomic nervous system functions such as heart rate, blood pressure, or breathing activity. Large, well-designed studies are needed before conclusions can be drawn.



Reiki may contribute to reduced perception of pain, improved quality of life, and reduced fatigue in cancer patients. More studies are needed.


Cognitive disorders (mild cognitive impairment)

Early research suggests that Reiki therapy may improve behavioral and memory problems in patients with mild cognitive impairment or mild Alzheimer's disease. However, additional studies are needed to confirm these findings.


Depression and stress

There is evidence that Reiki can reduce symptoms of distress when compared to placebo. More information is needed before a conclusion can be drawn.



Reiki instruction may help HIV/AIDS patients reduce pain or anxiety, but results are unclear.



Patients in a preliminary ("phase II") trial of Reiki in combination with standard pain medications (with opioids) were reported to experience improved pain control. Further research is needed to confirm these findings.


Stroke recovery

In a randomized controlled trial, Reiki did not have any clinically useful effect on stroke recovery in patients receiving appropriate rehabilitation therapy. Selective positive effects on mood and energy were noted.


*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).


The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

  • Addiction, adjunct in surgery, alcoholism, allergies, anemia, anger, anxiety, arthritis, asthma, bone marrow transplant support, breast cancer, brain damage, broken bones, burn pain, cardiopulmonary resuscitation, cardiovascular disease, cardiovascular risk reduction, carpal tunnel syndrome, cellulitis, cervical dysplasia, chemical burns, chronic pain, connective tissue disorders, convulsions, dementia, dental procedures, diabetes, diabetic neuropathy, diabetic wound healing, emotional problems, emphysema, epilepsy, fatigue, fibromyalgia, fractures (wrist), gallstones, grief, guilt, Guillain-Barre syndrome, headache, heart attack, hemophilia, hemorrhoids, hernia, herpes zoster, hiccough, high blood pressure, hysterectomy, impotence, labor, mental problems, migraine headache, multiple sclerosis, muscle spasms, neonatal disorders, nervous system function, neuropathy, nosebleeds, post-operative pain, post-traumatic stress disorder, pregnancy, promoting healing, prostate problems, psoriasis, radiation sickness, rash, recovering from anesthesia, reduction of adverse effects of chemotherapy and radiation, reflex sympathetic dystrophy, relaxation, rheumatoid arthritis, sickle cell anemia, sinus congestion, spinal cord injury, suicide prevention, systemic lupus erythematosus, trauma, tremor, ulcers, varicose veins, venereal diseases, warts, wound healing.


Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.

  • Reiki is not recommended as the sole treatment approach for potentially serious medical conditions and should not delay the time it takes to consult with a healthcare professional or receive established therapies. Serious adverse effects have not been reported in association with Reiki. Some practitioners believe that Reiki should be used cautiously in individuals with psychiatric illnesses due to a risk of bringing out underlying psychopathology, although this risk has not been formally reported in the published literature. People receiving Reiki treatment may need dosing adjustments of pain or anxiety medication.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).


Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Abdi S, Zhou Y. Management of pain after burn injury. Curr Opin Anaesthesiol 2002 Oct;15(5):563-7. View Abstract

  2. Astin JA, Harkness E, Ernst E. The efficacy of "distant healing": a systematic review of randomized trials. Ann Intern Med 6-6-2000;132(11):903-910. View Abstract

  3. Brewitt B, Vittetoe T, Hartwell B. The efficacy of Reiki hands-on healing: improvements in spleen and nervous system function as quantified by electrodermal screening [abstract]. Alternative Therapies in Health and Medicine 1997;3:89.

  4. Crawford SE, Leaver VW, Mahoney SD. Using Reiki to decrease memory and behavior problems in mild cognitive impairment and mild Alzheimer's disease. J Altern Complement Med 2006 Nov;12(9):911-3. View Abstract

  5. Kennedy P. Working with survivors of torture in Sarajevo with Reiki. Complement Ther Nurs.Midwifery 2001;7(1):4-7. View Abstract

  6. Krucoff MW, Crater SW, Gallup D, et al. Music, imagery, touch, and prayer as adjuncts to interventional cardiac care: the Monitoring and Actualisation of Noetic Trainings (MANTRA) II randomised study. Lancet 7-16-2005;366(9481):211-217. View Abstract

  7. Mackay N, Hansen S, McFarlane O. Autonomic nervous system changes during Reiki treatment: a preliminary study. J Altern Complement Med 2004;10(6):1077-1081. View Abstract

  8. Mansour AA, Beuche M, Laing G, et al. A study to test the effectiveness of placebo Reiki standardization procedures developed for a planned Reiki efficacy study. J Altern Complement Med. 1999;5(2):153-164. View Abstract

  9. Olson K, Hanson J. Using Reiki to manage pain: a preliminary report. Cancer Prev Control 1997;1(2):108-113. View Abstract

  10. Olson K, Hanson J, Michaud M. A phase II trial of Reiki for the management of pain in advanced cancer patients. J Pain Symptom Manage 2003;26(5):990-997. View Abstract

  11. Schlitz MJ, Braud WG. Reiki-plus natural healing: an ethnographic/experimental study. PSI Research 1985;4:100-123.

  12. Shore AG. Long-term effects of energetic healing on symptoms of psychological depression and self-perceived stress. Altern Ther Health Med. 2004;10(3):42-48. View Abstract

  13. Tsang KL, Carlson LE, Olson K. Pilot crossover trial of Reiki versus rest for treating cancer-related fatigue. Integr Cancer Ther 2007 Mar;6(1):25-35. View Abstract

  14. Vitale AT, O'Connor PC. The effect of Reiki on pain and anxiety in women with abdominal hysterectomies: a quasi-experimental pilot study. Holist Nurs Pract 2006 Nov-Dec;20(6):263-72; quiz 273-4. View Abstract

  15. Wardell DW, Engebretson J. Biological correlates of Reiki Touch(sm) healing. J Adv Nurs 2001;33(4):439-445. View Abstract

Copyright © 2013 Natural Standard (www.naturalstandard.com)

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.


March 22, 2017