Reiki has no known harmful effects. The National Center for Complementary and Integrative Health, the U.S. government’s leading authority on complementary therapies, states this plainly. Clinical trials consistently report no adverse events, and the practice involves only light touch or no touch at all, making physical injury essentially impossible. The one real risk has nothing to do with reiki itself: it comes from using reiki as a replacement for proven medical treatment rather than alongside it.
What Happens During a Session
Reiki is a relaxation technique where a practitioner places their hands lightly on or just above different areas of your body, typically your head, torso, and back. Sessions usually last 30 to 60 minutes. You stay fully clothed, and the practitioner doesn’t manipulate your muscles, adjust your joints, or apply pressure. There’s no ingesting anything, no needles, and no equipment. This is part of why the safety profile is so clean compared to other complementary therapies like herbal supplements (which can interact with medications) or chiropractic manipulation (which carries a small risk of injury).
What Clinical Research Shows
A 2025 meta-analysis of randomized controlled trials found that reiki showed no harmful effects across studies involving cancer patients, people with chronic conditions, and healthy adults. One study on biofield energy healing tracked participants’ kidney function, heart function, liver function, blood sugar markers, and cholesterol levels at the start, at 90 days, and at 180 days. No safety concerns emerged in any of those markers.
The research on vulnerable populations tells a similar story. A pilot study testing reiki on newborns at risk for withdrawal symptoms (from prenatal substance exposure) found it was safe when administered with standard monitoring. Researchers had clear stopping criteria in place, including changes in heart rate or oxygen levels, but none of the sessions needed to be halted for safety reasons. A separate trial of daily reiki for premature newborns over 10 days reported no serious adverse events. If reiki is safe enough for high-risk newborns under clinical monitoring, healthy adults have very little to worry about from the practice itself.
Where Reiki Is Used in Healthcare
More than 800 hospitals in the United States, roughly 15% of all hospitals, now offer reiki as part of their integrative medicine programs. Cancer Research UK notes that reiki is generally safe for most people with cancer and that there are no reports of harmful side effects. These aren’t fringe wellness clinics. Major medical centers incorporate reiki alongside conventional treatment specifically because the risk is negligible and some patients report feeling less anxious and more comfortable during difficult treatments like chemotherapy.
The Actual Risk: Delaying Real Treatment
The only documented concern with reiki is indirect. If someone with a serious health condition chooses reiki instead of evidence-based medical care, that delay can cause real harm. This isn’t a problem unique to reiki; it applies to any complementary therapy someone might substitute for conventional treatment.
Reiki works best as a complement to medical care, not a replacement. It may help with anxiety, stress, pain perception, and general well-being, but it does not treat infections, shrink tumors, or manage chronic disease on its own. The distinction matters most when the stakes are high. Someone using reiki to feel calmer during cancer treatment is in a very different situation than someone using reiki instead of cancer treatment.
What Ethical Practitioners Should and Shouldn’t Do
Reputable reiki practitioners follow a code of ethics that directly addresses safety boundaries. According to the International Association of Reiki Professionals, practitioners should never diagnose medical or psychological conditions, never prescribe or suggest changes to medications, and never interfere with treatment from a licensed healthcare provider. They should inform clients that reiki does not provide a cure and is not a substitute for medical care. They should also never ask you to disrobe or touch your genital area or breasts.
If a practitioner tells you to stop taking a prescribed medication, skip a medical appointment, or claims they can cure a specific disease, that’s a serious red flag. A trustworthy practitioner will encourage you to continue working with your doctor and frame reiki as a supportive practice rather than a medical intervention.
Pregnancy, Children, and Other Sensitive Groups
There are no established contraindications for reiki in pregnancy, childhood, or old age. Because the technique doesn’t involve physical manipulation, substances, or devices, there’s nothing in the process that would pose a unique risk to pregnant people or children. The newborn studies mentioned earlier represent some of the most vulnerable patients imaginable, and even in those cases, researchers found no safety issues.
That said, if you’re pregnant or managing a complex health situation, letting your healthcare provider know you’re receiving reiki is still good practice. Not because reiki is likely to cause a problem, but because your care team should have the full picture of everything you’re doing for your health.