Reiki

Our assessments of evidence for each medical benefit fall into one of these categories:

• Strong evidence: consistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analysesa statistical analysis that combines the results of two or more research studies; the results of smaller research studies addressing the same or similar questions can be analyzed as though they are one bigger, more powerful study of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results
• Good evidence: significant effects in one large or several mid-sized and well-designed clinical studies ( randomized controlled trialsa study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects with an appropriate placebo or other strong comparison control or observational studies that control for confounds)
• Modest evidence: significant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observationala type of study in which individuals are observed or certain outcomes are measured, but no attempt is made to affect the outcome (for example, no treatment is given); an example is a study that records people’s diets, but doesn’t try to alter their diets, and looks for patterns of disease or other outcomes related to different foods studies), or several small studies aggregated into a meta-analysis
• Preliminary evidence: significant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect
• Weak evidence: one or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects
• Insufficient evidence: preclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example)

Learn more about how we research and rate therapies and practices in How We Rate Therapies ›

No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on salivary cortisol among healthy people treated with Reiki in a small study

• No evidence of an effect on salivary cortisol among healthy people treated with 30 minutes of Reiki compared to baseline in a small uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design¹Wardell DW, Engebretson J. Biological correlates of Reiki Touch(sm) healing. Journal of Advanced Nursing. 2001 Feb;33(4):439-45.

Weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of a higher marker of immune activation among healthy people treated with Reiki

• A higher marker of immune activation (salivary immunoglobulin A, IgA) among healthy people treated with 30 minutes of Reiki compared to baseline in a small uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design²Wardell DW, Engebretson J. Biological correlates of Reiki Touch(sm) healing. Journal of Advanced Nursing. 2001 Feb;33(4):439-45.

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of fewer or less severe symptoms among people with breast cancer treated with Reiki

• Better (lower) symptom scores among people with breast cancer treated with 6 sessions of Reiki therapy compared to controls in a small controlled triala study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial³Karaman S, Tan M. Effect of Reiki therapy on quality of life and fatigue levels of breast cancer patients receiving chemotherapy. Cancer Nursing. 2021 Nov-Dec 01;44(6):E652-E658.

Weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of less anxiety among people with cancer treated with Reiki

• A weak trendan apparent change due to a therapy, close to but not achieving full statistical significance (this is the CancerChoices definition; other researchers and studies may define this differently toward less anxiety during radiotherapy among men with prostate cancer who were classified as anxious at baseline treated with Reiki compared to baseline in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects⁴Beard C, Stason WB et al. Effects of complementary therapies on clinical outcomes in patients being treated with radiation therapy for prostate cancer. Cancer 2011 Jan; 117: 96-102.
• Lower anxiety scores among people with cancer treated with Reiki, but not with resting, compared to baseline in a small comparison trial⁵Tsang KL, Carlson LE, Olson K. Pilot crossover trial of Reiki versus rest for treating cancer-related fatigue. Integrative Cancer Therapies. 2007;6:25-35.
• Less reported anxiety among people with cancer treated with a single Reiki session compared to baseline in a mid-sized uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design⁶Rosenbaum MS, Velde J. The effects of yoga, massage, and Reiki on patient well-being at a cancer resource center. Clinical Journal of Oncology Nursing. 2016 Jun 1;20(3):E77-81.
• Less anxiety during chemotherapy among people with cancer treated with 4 separate 30-minute Reiki sessions compared to baseline in a small uncontrolled trial⁷Birocco N, Guillame C et al. The effects of Reiki therapy on pain and anxiety in patients attending a day oncology and infusion services unit. American Journal of Hospice & Palliative Care. 2012 Jun;29(4):290-4.
• Lower anxiety during cancer treatment primarily among people with cancer and also their caregivers and staff treated with Reiki for the first time compared to baseline in a small uncontrolled trial⁸Fleisher KA, Mackenzie ER et al. Integrative Reiki for cancer patients: a program evaluation. Integrative Cancer Therapies. 2014 Jan;13(1):62-7.

Symptoms among caregivers: preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower blood pressure and pulse rates among women who were primary caregivers of patients with cancer treated with Reiki

• Lower systolic and diastolic blood pressure and pulse rate among women who were primary caregivers of patients with cancer treated with Reiki to 9 main points for 45 minutes, once a week for 6 weeks compared to sham Reiki in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects⁹Özcan Yüce U, Taşcı S. Effect of Reiki on the stress level of caregivers of patients with cancer: qualitative and single-blind randomized controlled trial. Complementary Therapies in Medicine. 2021 May;58:102708.

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently)  of better mood or less depression among people with cancer treated with Reiki

• Better mood during chemotherapy among people with breast cancer treated with Reiki compared to usual care in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects¹⁰Orsak G, Stevens AM, Brufsky A, Kajumba M, Dougall AL. The effects of Reiki therapy and companionship on quality of life, mood, and symptom distress during chemotherapy. Journal of Evidence-based Complementary and Alternative Medicine. 2015 Jan; 20: 20-7.
• Better reported mood among people with cancer treated with a single Reiki session compared to baseline in a mid-sized uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design¹¹Rosenbaum MS, Velde J. The effects of yoga, massage, and Reiki on patient well-being at a cancer resource center. Clinical Journal of Oncology Nursing. 2016 Jun 1;20(3):E77-81.
• Lower depression during cancer treatment primarily among people with cancer and also their caregivers treated with Reiki for the first time compared to baseline in a small uncontrolled trial¹²Fleisher KA, Mackenzie ER et al. Integrative Reiki for cancer patients: a program evaluation. Integrative Cancer Therapies. 2014 Jan;13(1):62-7.

No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on depression among women with low baseline anxiety levels undergoing breast biopsy treated with Reiki

• No evidence of an effect on depression among women with low baseline anxiety levels undergoing breast biopsy treated with Reiki compared to usual treatment in a small RCT¹³Potter PJ. Breast biopsy and distress: feasibility of testing a Reiki intervention. Journal of Holistic Nursing. 2007 Dec;25(4):238-48; discussion 249-51.

Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of less fatigue among people with cancer treated with Reiki

• Less fatigue among people with stage 3 or 4 cancer receiving palliative care treated with Reiki compared to controls in a mid-sized RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects¹⁴Utli H, Dinç M, Utli MDA. The effect of acupressure or reiki interventions on the levels of pain and fatigue of cancer patients receiving palliative care: a randomized controlled study. Explore (NY). 2023 Jan-Feb;19(1):91-99.
• Less fatigue among people with breast cancer treated with 6 sessions of Reiki therapy compared to controls in a small controlled triala study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial¹⁵Karaman S, Tan M. Effect of Reiki therapy on quality of life and fatigue levels of breast cancer patients receiving chemotherapy. Cancer Nursing. 2021 Nov-Dec 01;44(6):E652-E658.
• Apparently less fatigue (lacking a clear statement of significance) among people with cancer treated with 5 distant ReikiReiki therapy delivered remotely from a location distant from the recipient sessions, one each night for 30 minutes, compared to controls in a small RCT¹⁶Demir M, Can G, Kelam A, Aydıner A. Effects of distant Reiki on pain, anxiety and fatigue in oncology patients in turkey: a pilot study. Asian Pacific Journal of Cancer Prevention. 2015;16(12):4859-62.
• Lower fatigue during cancer treatment primarily among people with cancer and also their caregivers treated with Reiki for the first time compared to baseline in a small uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design¹⁷Fleisher KA, Mackenzie ER et al. Integrative Reiki for cancer patients: a program evaluation. Integrative Cancer Therapies. 2014 Jan;13(1):62-7.
• Lower scores for “tiredness” and similar fatigue scores among people with cancer treated with Reiki compared to resting in a small comparison trial¹⁸Tsang KL, Carlson LE, Olson K. Pilot crossover trial of Reiki versus rest for treating cancer-related fatigue. Integrative Cancer Therapies. 2007;6:25-35.

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower neurotoxicity scores among people with persistent symptoms of chemotherapy-induced peripheral neuropathy treated with Reiki

• Maintained neurotoxicity scores among people with persistent symptoms of chemotherapy-induced peripheral neuropathy lasting 3 months or more treated with weekly, hour-long sessions of Reiki for 6 weeks compared to worse scores among people receiving education only in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects¹⁹Clark PG, Cortese-Jimenez G, Cohen E. Effects of Reiki, yoga, or meditation on the physical and psychological symptoms of chemotherapy-induced peripheral neuropathy: a randomized pilot study. Journal of Evidence-Based Complementary & Alternative Medicine. 2012;17(3):161-171.

Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of less pain among people with cancer treated with Reiki

• Less pain and analgesic use among people with stage 3 or 4 cancer receiving palliative care treated with Reiki compared to controls in a mid-sized RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects²⁰Utli H, Dinç M, Utli MDA. The effect of acupressure or reiki interventions on the levels of pain and fatigue of cancer patients receiving palliative care: a randomized controlled study. Explore (NY). 2023 Jan-Feb;19(1):91-99.
• Less pain among people with cancer treated with Reiki on 3 consecutive days compared to controls in a mid-sized controlled triala study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial²¹Buyukbayram Z, Citlik Saritas S. The effect of Reiki and guided imagery intervention on pain and fatigue in oncology patients: a non-randomized controlled study. Explore (NY). 2021 Jan-Feb;17(1):22-26.
• Less short- and medium-term pain but no evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on long-term pain during hematopoietic stem cell transplantation among children treated with an average of more than 9 Reiki sessions compared to baseline in a small uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design²²Zucchetti G, Candela F et al. The power of Reiki: feasibility and efficacy of reducing pain in children with cancer undergoing hematopoietic stem cell transplantation. Journal of Pediatric Oncology Nursing. 2019 Sep/Oct;36(5):361-368.
• Less reported pain among people with cancer treated with a single Reiki session compared to baseline in a mid-sized uncontrolled trial²³Rosenbaum MS, Velde J. The effects of yoga, massage, and Reiki on patient well-being at a cancer resource center. Clinical Journal of Oncology Nursing. 2016 Jun 1;20(3):E77-81.
• Apparently less pain (lacking a clear statement of significance) among people with cancer treated with 5 distant ReikiReiki therapy delivered remotely from a location distant from the recipient sessions, one each night for 30 minutes, compared to controls in a small RCT²⁴Demir M, Can G, Kelam A, Aydıner A. Effects of distant Reiki on pain, anxiety and fatigue in oncology patients in turkey: a pilot study. Asian Pacific Journal of Cancer Prevention. 2015;16(12):4859-62.
• A weak trendan apparent change due to a therapy, close to but not achieving full statistical significance (this is the CancerChoices definition; other researchers and studies may define this differently toward less pain during chemotherapy among people with cancer treated with 4 separate 30-minute Reiki sessions compared to baseline in a small uncontrolled trial²⁵Birocco N, Guillame C et al. The effects of Reiki therapy on pain and anxiety in patients attending a day oncology and infusion services unit. American Journal of Hospice & Palliative Care. 2012 Jun;29(4):290-4.
• Lower pain during cancer treatment primarily among people with cancer and also their caregivers treated with Reiki for the first time compared to baseline in a small uncontrolled trial²⁶Fleisher KA, Mackenzie ER et al. Integrative Reiki for cancer patients: a program evaluation. Integrative Cancer Therapies. 2014 Jan;13(1):62-7.
• Lower pain scores among people with cancer treated with Reiki compared to resting in a small comparison trial²⁷Tsang KL, Carlson LE, Olson K. Pilot crossover trial of Reiki versus rest for treating cancer-related fatigue. Integrative Cancer Therapies. 2007;6:25-35.
• Short-term pain relief but no evidence of reduced use of opioids during standard opioid treatment among people with advanced cancer treated with Reiki compared to rest in a small RCT²⁸Olson K, Hanson J, Mchaud M. A phase II trial of Reiki for the management of pain in advanced cancer patients. Journal of Pain and Symptom Management. 2003;26:990-7.

Children: weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of less pain among nonverbal children receiving palliative care treated with Reiki

• A  weak trendan apparent change due to a therapy, close to but not achieving full statistical significance (this is the CancerChoices definition; other researchers and studies may define this differently toward less pain among nonverbal children receiving palliative care treated with 2 separate 24-minute Reiki sessions at the children’s home compared to baseline in a small uncontrolled trial²⁹Thrane SE, Maurer SH, Ren D, Danford CA, Cohen SM. Reiki therapy for symptom management in children receiving palliative care: a pilot study. American Journal of Hospice & Palliative Care. 2017 May;34(4):373-379.

Without regard to treatment phase: preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of better quality of life and function among people with cancer treated with Reiki

• Better (lower) general function scores and better (higher) general well-being scores among people with breast cancer treated with 6 sessions of Reiki therapy compared to controls in a small controlled triala study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial³⁰Karaman S, Tan M. Effect of Reiki therapy on quality of life and fatigue levels of breast cancer patients receiving chemotherapy. Cancer Nursing. 2021 Nov-Dec 01;44(6):E652-E658.
• Higher general, physical, environmental, and social function scores but no evidence of an effect on psychological scores among people with cancer treated with Reiki twice a week for 60 minutes for 4 weeks compared to sham Reiki in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects³¹Alarcão Z, Fonseca JRS. The effect of Reiki therapy on quality of life of patients with blood cancer: results from a randomized controlled trial. European Journal of Integrative Medicine. 2016;8(3):239-249.
• Better quality of life scores among people with cancer treated with Reiki compared to resting in a small comparison trial³²Tsang KL, Carlson LE, Olson K. Pilot crossover trial of Reiki versus rest for treating cancer-related fatigue. Integrative Cancer Therapies. 2007;6:25-35.
• Better overall health and quality of life among people with cancer treated with a single Reiki session compared to baseline in a mid-sized uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design³³Rosenbaum MS, Velde J. The effects of yoga, massage, and Reiki on patient well-being at a cancer resource center. Clinical Journal of Oncology Nursing. 2016 Jun 1;20(3):E77-81.

During treatment: preliminary evidence of higher comfort and well-being and better quality of life during chemotherapy among people treated with Reiki or sham Reiki

• Higher comfort and well-being during outpatient chemotherapy among people treated with either Reiki or sham Reiki compared to usual care in a mid-sized RCT; the researchers concluded that “the presence of an RN providing one-on-one support during chemotherapy was influential in raising comfort and well-being levels, with or without an attempted healing energy field”³⁴Catlin A, Taylor-Ford RL. Investigation of standard care versus sham Reiki placebo versus actual Reiki therapy to enhance comfort and well-being in a chemotherapy infusion center. Oncology Nursing Forum 2011 May; 38: E212-E220.
• Better quality of life during chemotherapy among people with breast cancer treated with Reiki compared to usual care in a small RCT³⁵Orsak G, Stevens AM, Brufsky A, Kajumba M, Dougall AL. The effects of Reiki therapy and companionship on quality of life, mood, and symptom distress during chemotherapy. Journal of Evidence-based Complementary and Alternative Medicine. 2015 Jan; 20: 20-7.

After treatment: weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of better quality of life but no evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on mindfulness or capacity to attend to events in the present moment among people with persistent symptoms of chemotherapy-induced peripheral neuropathy treated with Reiki

• A weak trendan apparent change due to a therapy, close to but not achieving full statistical significance (this is the CancerChoices definition; other researchers and studies may define this differently toward better quality of life but no evidence of an effect on mindfulness or capacity to attend to events in the present moment among people with persistent symptoms of chemotherapy-induced peripheral neuropathy lasting 3 months or more treated with weekly, hour-long sessions of Reiki for 6 weeks compared to baseline in an uncontrolled analysis within a small RCT³⁶Clark PG, Cortese-Jimenez G, Cohen E. Effects of Reiki, yoga, or meditation on the physical and psychological symptoms of chemotherapy-induced peripheral neuropathy: a randomized pilot study. Journal of Evidence-Based Complementary & Alternative Medicine. 2012;17(3):161-171.

Advanced cancer: preliminary evidence of better quality of life among people with advanced cancer treated with Reiki

• Better quality of life during standard opioid treatment among people with advanced cancer treated with Reiki compared to rest in a small RCT³⁷Olson K, Hanson J, Mchaud M. A phase II trial of Reiki for the management of pain in advanced cancer patients. Journal of Pain and Symptom Management. 2003;26:990-7.

Stress: preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of less stress among people with cancer treated with Reiki

• Less reported stress among people with cancer treated with a single Reiki session compared to baseline in a mid-sized uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design³⁸Rosenbaum MS, Velde J. The effects of yoga, massage, and Reiki on patient well-being at a cancer resource center. Clinical Journal of Oncology Nursing. 2016 Jun 1;20(3):E77-81.
• Apparently less stress (lacking a clear statement of significance) among people with cancer treated with 5 distant ReikiReiki therapy delivered remotely from a location distant from the recipient sessions, one each night for 30 minutes, compared to controls in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects³⁹Demir M, Can G, Kelam A, Aydıner A. Effects of distant Reiki on pain, anxiety and fatigue in oncology patients in turkey: a pilot study. Asian Pacific Journal of Cancer Prevention. 2015;16(12):4859-62.

Distress: insufficient evidencepreclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example) (this is the CancerChoices definition; other researchers and studies may define this differently) of an effect on psychological distress among people with cancer treated with Reiki

• Lower distress during cancer treatment primarily among people with cancer treated with Reiki for the first time compared to baseline in a small uncontrolled trial⁴⁰Fleisher KA, Mackenzie ER et al. Integrative Reiki for cancer patients: a program evaluation. Integrative Cancer Therapies. 2014 Jan;13(1):62-7.
• No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on psychological distress among people with persistent symptoms of chemotherapy-induced peripheral neuropathy lasting 3 months or more treated with weekly, hour-long sessions of Reiki for 6 weeks compared to education only in a small RCT⁴¹Clark PG, Cortese-Jimenez G, Cohen E. Effects of Reiki, yoga, or meditation on the physical and psychological symptoms of chemotherapy-induced peripheral neuropathy: a randomized pilot study. Journal of Evidence-Based Complementary & Alternative Medicine. 2012;17(3):161-171.

Relaxation among children: weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of more relaxation among nonverbal children receiving palliative care treated with Reiki

• Markers of more relaxation (slower respiratory and heart rates) among nonverbal children receiving palliative care treated with 2 separate 24-minute Reiki sessions at the children’s home compared to baseline in a small uncontrolled trial⁴²Thrane SE, Maurer SH, Ren D, Danford CA, Cohen SM. Reiki therapy for symptom management in children receiving palliative care: a pilot study. American Journal of Hospice & Palliative Care. 2017 May;34(4):373-379.

Symptoms among caregivers: preliminary evidence of less stress or distress among caregivers of people with cancer treated with Reiki

• Lower Caregiver Strain Index (CSI) scores but no evidence of an effect on saliva cortisol levels among women who were primary caregivers of patients with cancer treated with Reiki to 9 main points for 45 minutes, once a week for 6 weeks compared to sham Reiki in a small RCT⁴³Özcan Yüce U, Taşcı S. Effect of Reiki on the stress level of caregivers of patients with cancer: Qualitative and single-blind randomized controlled trial. Complementary Therapies in Medicine. 2021 May;58:102708.
• Lower distress during cancer treatment primarily among caregivers of people with cancer treated with Reiki for the first time compared to baseline in a small uncontrolled trial⁴⁴Fleisher KA, Mackenzie ER et al. Integrative Reiki for cancer patients: a program evaluation. Integrative Cancer Therapies. 2014 Jan;13(1):62-7.

Symptoms as a whole: no evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on illness symptoms such as fever, headache, and runny nose among people with high anxiety and/or depression treated with Reiki

• No evidence of an effect on 20 illness symptoms including fever, headache, and runny nose among people with high anxiety and/or depression treated with 6 separate 30-minute Reiki sessions over 2 to 8 weeks compared to controls in a small RCTrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects⁴⁵Bowden D, Goddard L, Gruzelier J. A randomised controlled single-blind trial of the efficacy of reiki at benefitting mood and well-being. Evidence-Based Complementary and Alternative Medicine. 2011;2011:381862.

Anxiety

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of less anxiety among people treated with Reiki

• Less anxiety among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled triala study in which a therapy is used, but without a comparison group against which to judge outcomes; an uncontrolled trial is considered a weak study design⁴⁶Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.
• Less anxiety among community-dwelling older adults treated with Reiki for 30 minutes 1 day per week for 8 weeks compared to controls in a small RCT⁴⁷Richeson NE, Spross JA, Lutz K, Peng C. Effects of Reiki on anxiety, depression, pain, and physiological factors in community-dwelling older adults. Research in Gerontological Nursing. 2010 Jul;3(3):187-99.
• Less anxiety among healthy people treated with 30 minutes of Reiki compared to baseline in a small uncontrolled trial⁴⁸Wardell DW, Engebretson J. Biological correlates of Reiki Touch(sm) healing. Journal of Advanced Nursing. 2001 Feb;33(4):439-45.

Preliminary evidence of less anxiety among people undergoing surgery treated with Reiki

• No evidence of an effect on anxiety in the days before cardiac surgery when Reiki was used with conventional care compared to conventional care alone in a small controlled triala study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial⁴⁹Santos CBRD, Gomes ET, Bezerra SMMDS, Püschel VAA. Reiki protocol for preoperative anxiety, depression, and well-being: a non-randomized controlled trial. Revista da Escola de Enfermagem da USP. 2020 Oct 26;54:e03630. Portuguese, English.
• Lower state anxiety, blood pressure, respiration rate, and pain scores among people undergoing knee replacement surgery treated with Reiki, but not with sham Reiki or standard of care, compared to baseline in a small uncontrolled trial⁵⁰Baldwin AL, Vitale A, Brownell E, Kryak E, Rand W. Effects of Reiki on pain, anxiety, and blood pressure in patients undergoing knee replacement: a pilot study. Holististic Nursing Practice. 2017 Mar/Apr;31(2):80-89.

Breathlessness: weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of less breathlessness among people treated with Reiki

• Less breathlessness among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled trial⁵¹Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.

Cardiovascular side effects: preliminary evidence of lower blood pressure among people treated with Reiki, except no evidence of an effect among older adults

• Lower blood pressure and respiration rate among people undergoing knee replacement surgery, but not with sham Reiki or standard of care, compared to baseline in a small uncontrolled trial⁵²Baldwin AL, Vitale A, Brownell E, Kryak E, Rand W. Effects of Reiki on pain, anxiety, and blood pressure in patients undergoing knee replacement: a pilot study. Holististic Nursing Practice. 2017 Mar/Apr;31(2):80-89.
• No evidence of an effect on heart rate or blood pressure among community-dwelling older adults treated with Reiki for 30 minutes 1 day per week for 8 weeks compared to controls in a small RCT⁵³Richeson NE, Spross JA, Lutz K, Peng C. Effects of Reiki on anxiety, depression, pain, and physiological factors in community-dwelling older adults. Research in Gerontological Nursing. 2010 Jul;3(3):187-99.
• Lower heart rate and diastolic blood pressure among people treated with Reiki compared to rest only or sham Reiki in a small RCT⁵⁴Mackay N, Hansen S, McFarlane O. Autonomic nervous system changes during Reiki treatment: a preliminary study. Journal of Alternative and Complementary Medicine. 2004 Dec;10(6):1077-81.
• Lower systolic blood pressure among healthy people treated with 30 minutes of Reiki compared to baseline in a small uncontrolled trial⁵⁵Wardell DW, Engebretson J. Biological correlates of Reiki Touch(sm) healing. Journal of Advanced Nursing. 2001 Feb;33(4):439-45.

Changes in appetite: weak evidence of better appetite among people treated with Reiki

• Better appetite among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled trial⁵⁶Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.

Cognitive difficulties: preliminary evidence of better performance regarding mental functioning, memory, and behavior problems among people with mild cognitive impairment or mild Alzheimer’s disease treated with Reiki

• Better performance regarding mental functioning, memory, and behavior problems among people with mild cognitive impairment or mild Alzheimer’s disease treated with 4 weekly treatments of Reiki compared to controls in a small controlled trial⁵⁷Crawford SE, Leaver VW, Mahoney SD. Using Reiki to decrease memory and behavior problems in mild cognitive impairment and mild Alzheimer’s disease. Journal of Alternative and Complementary Medicine. 2006 Nov;12(9):911-3.

Depression: preliminary evidence of fewer symptoms of depression among people treated with Reiki

• Better overall mood among people with high anxiety and/or depression treated with 6 separate 30-minute Reiki sessions over 2 to 8 weeks compared to controls in a small RCT⁵⁸Bowden D, Goddard L, Gruzelier J. A randomised controlled single-blind trial of the efficacy of reiki at benefitting mood and well-being. Evidence-Based Complementary and Alternative Medicine. 2011;2011:381862.
• Less depression among community-dwelling older adults treated with Reiki for 30 minutes 1 day per week for 8 weeks compared to controls in a small RCT⁵⁹Richeson NE, Spross JA, Lutz K, Peng C. Effects of Reiki on anxiety, depression, pain, and physiological factors in community-dwelling older adults. Research in Gerontological Nursing. 2010 Jul;3(3):187-99.
• No evidence of an  effect on depression in the days before cardiac surgery when Reiki was used with conventional care compared to conventional care alone in a small controlled trial⁶⁰Santos CBRD, Gomes ET, Bezerra SMMDS, Püschel VAA. Reiki protocol for preoperative anxiety, depression, and well-being: a non-randomized controlled trial. Revista da Escola de Enfermagem da USP. 2020 Oct 26;54:e03630. Portuguese, English.
• Less depression and better emotional states (greater positive affect and less negative affect) among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled trial⁶¹Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.

Fatigue: weak evidence of less drowsiness and tiredness among people treated with Reiki

• Less drowsiness and tiredness among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled trial⁶²Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.

Gastrointestinal symptoms: weak evidence of less nausea among people treated with Reiki

• Less nausea among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled trial⁶³Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.

Neuropathy: no evidence of an effect on pain, 6-minute walk test, well-being scores, or Diabetes Treatment Satisfaction Questionnaire among people with type 2 diabetes and painful diabetic neuropathy treated with Reiki in a mid-sized study

• No evidence of an effect on pain, 6-minute walk test, well-being scores, or Diabetes Treatment Satisfaction Questionnaire among people with type 2 diabetes and painful diabetic neuropathy treated with 25 minutes of Reiki twice in the first week and then weekly for the next 11 weeks compared to mimic Reiki or usual care in a mid-sized RCT⁶⁴Gillespie EA, Gillespie BW, Stevens MJ. Painful diabetic neuropathy: impact of an alternative approach. Diabetes Care. 2007 Apr;30(4):999-1001.

Pain: modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of less pain, including surgery-related pain, among people treated with Reiki

• Less pain and greater comfort among people undergoing laparoscopic gallbladder removal (cholecystectomy) with Reiki compared to no intervention in a mid-sized RCT⁶⁵Topdemir EA, Saritas S. The effect of acupressure and Reiki application on patient’s pain and comfort level after laparoscopic cholecystectomy: a randomized controlled trial. Complementary Therapies in Clinical Practice. 2021 May;43:101385.
• Less pain and more comfort among people undergoing gallbladder removal (cholecystectomy) with Reiki compared to controls in a small RCT
• ⁶⁶Topdemir EA, Saritas S. The effect of acupressure and Reiki application on patient’s pain and comfort level after laparoscopic cholecystectomy: a randomized controlled trial. Complementary Therapies in Clinical Practice. 2021 May;43:101385.
• A weak trend toward less pain not specific to cancer among people treated with Reiki compared to controls in a meta-analysisa statistical analysis that combines the results of two or more research studies; the results of smaller research studies addressing the same or similar questions can be analyzed as though they are one bigger, more powerful study of 4 RCTs⁶⁷Demir Doğan M. The effect of Reiki on pain: a meta-analysis. Complementary Therapies in Clinical Practice. 2018 May;31:384-387.
• Lower pain scores and use of analgesics, and longer intervals between analgesic use among women recovering from Cesarean section treated with Reiki compared to sham Reiki or usual care in a small RCT⁶⁸Sagkal Midilli T, Ciray Gunduzoglu N. Effects of Reiki on pain and vital signs when applied to the incision area of the body after cesarean section surgery: a single-blinded, randomized, double-controlled study. Holistic Nursing Practice. 2016 Nov/Dec;30(6):368-378.
• Less reported pain but no difference in analgesic use among people undergoing total knee arthroplasty with Reiki compared to standard care in a small RCT⁶⁹Notte BB, Fazzini C, Mooney RA. Reiki’s effect on patients with total knee arthroplasty: a pilot study. Nursing. 2016 Feb;46(2):17-23.
• Moderately less pain among people treated with Reiki, especially with more experienced practitioners, compared to sham or placeboa pill, medicine, or procedure—thought to be both harmless and ineffective—prescribed for the psychological benefit to the patient or as a sham treatment in a study to allow a comparison to a therapy of interest in a review of 3 RCTs and controlled trials⁷⁰So PS, Jiang Y, Qin Y. Touch therapies for pain relief in adults. Cochrane Database of Systematic Reviews. 2008 Oct 8;(4):CD006535.
• Lower pain intensity among people with pain and possibly other symptoms of various medical conditions treated with 10 sessions of Reiki compared to controls (no treatment), progressive muscle relaxation, or sham Reiki in a mid-sized RCT⁷¹Dressen LJ, Singg S. Effects of reiki on pain and selected affective and personality variables of chronically ill patients. Subtle Energies and Energy Medicine, 1998;9(1):51–83.

Quality of life and well-being: weak evidence of better well-being among people treated with Reiki

• Better well-being among people treated with a single Reiki session lasting 45 to 90 minutes compared to baseline in a large uncontrolled trial⁷²Dyer NL, Baldwin AL, Rand WL. A large-scale effectiveness trial of Reiki for physical and psychological health. Journal of Alternative and Complementary Medicine. 2019 Dec;25(12):1156-1162.

Sleep difficulties: no evidence of an effect on sleep scores among people with high anxiety and/or depression treated with Reiki

• No evidence of an effect on sleep scores among people with high anxiety and/or depression treated with 6 separate 30-minute Reiki sessions over 2 to 8 weeks compared to controls in a small RCT⁷³Bowden D, Goddard L, Gruzelier J. A randomised controlled single-blind trial of the efficacy of reiki at benefitting mood and well-being. Evidence-Based Complementary and Alternative Medicine. 2011;2011:381862.

Spiritual well-being: preliminary evidence of improved spiritual well-being among people preparing for cardiac surgery and treated with Reiki

• Improved spiritual well-being in the days before cardiac surgery among people treated with Reiki compared to baseline in a small controlled trial⁷⁴Santos CBRD, Gomes ET, Bezerra SMMDS, Püschel VAA. Reiki protocol for preoperative anxiety, depression, and well-being: a non-randomized controlled trial. Revista da Escola de Enfermagem da USP. 2020 Oct 26;54:e03630. Portuguese, English.

Stress: preliminary evidence of less stress among people treated with Reiki

• Lower scores on stress among people with moderate baseline stress scores and not using antidepressant or anti-anxiety drugs (anxiolytics) treated with massage and Reiki compared to massage alone in a small RCT⁷⁵Kurebayashi LFS, Gnatta JR et al. Massage and Reiki to reduce stress and improve quality of life: a randomized clinical trial. Revista da Escola de Enfermagem da USP. 2020 Oct 12;54:e03612. Portuguese, English.
• Fewer symptoms of psychological distress, continuing for 1 year, among people treated with hands-on Reiki or distance ReikiReiki therapy delivered remotely from a location distant from the recipient for an hour to an hour and a half each week for 6 weeks compared to distance Reiki placebo in a small RCT⁷⁶Shore AG. Long-term effects of energetic healing on symptoms of psychological depression and self-perceived stress. Alternative Therapies in Health and Medicine 2004;10(3):42-8.
• Greater self-reported physical relaxation but no evidence of an effect on mental relaxation among college students treated with 20 minutes of Reiki compared to sham Reiki, a meditation tape, or a music tape in a mid-sized controlled trial; the authors note that the students in the study did not report high levels of stress⁷⁷Witte D, Dundes L. Harnessing life energy or wishful thinking? Reiki, placebo Reiki, meditation, and music. Alternative and Complementary Therapies. 2001;7(5):304-309.

Mindfulness meditation, Reiki, acupuncture, and auriculotherapy: weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of lower depression among people with symptoms of depression after an intervention of mindfulness meditation, Reiki, acupuncture, and auriculotherapy

• Lower depression among people with symptoms of depression receiving no drug or psychotherapy treatment after an intervention of mindfulness meditation, Reiki, acupuncture, and auriculotherapy, but not following no intervention, compared to baseline in a small randomized trial⁷⁸Cardozo-Batista L, Tucci AM. Effectiveness of an alternative intervention in the treatment of depressive symptoms. Journal of Affective Disorders. 2020 Nov 1;276:562-569.