One of the most common criticisms of Reiki is also one of the most reasonable:
How can you scientifically study something when you do not fully understand how it works?
This is not a problem unique to Reiki.
Medical science has repeatedly studied interventions before fully understanding their mechanisms. Researchers can observe an effect before they understand exactly why it occurs.
But Reiki presents a particularly difficult research problem.
The intervention involves a practitioner.
The practitioner may use touch or no touch.
The recipient knows they are receiving a treatment.
The practitioner knows what they are doing.
The experience can be highly subjective.
And the proposed mechanism is not established within conventional biomedical science.
So how do you design a study that separates Reiki itself from everything surrounding the experience?
The Basic Question of Clinical Research
At the simplest level, researchers want to know whether an intervention produces an outcome beyond what would otherwise have occurred.
That sounds straightforward.
In practice, it is extraordinarily difficult.
Imagine a person receives a Reiki session and reports significantly less anxiety afterward.
What caused the change?
Was it Reiki?
Was it lying quietly for an hour?
Was it human attention?
Was it gentle touch?
Was it expectation?
Was it the therapeutic relationship?
Was it simply taking a break from a stressful environment?
Was it some combination of these factors?
A good study is designed to begin separating these possibilities.
Why Randomized Controlled Trials Matter
Randomized controlled trials can help researchers compare groups that receive different interventions or conditions.
Randomization reduces certain forms of selection bias.
A control group provides a comparison.
Blinding can reduce the influence of expectations.
Standardized protocols can reduce variation.
Appropriate outcome measures allow researchers to quantify changes.
These principles are not designed specifically for pharmaceutical research.
They can also be applied to complementary therapies.
The challenge is figuring out what the appropriate control actually is.
The Problem of Sham Reiki
This may be one of the most fascinating methodological issues in Reiki research.
Researchers can create a sham Reiki condition in which someone receives an experience designed to resemble Reiki without the practitioner intentionally practicing Reiki.
The idea is to determine whether outcomes differ between Reiki and a credible sham condition.
But creating a good sham is surprisingly difficult.
A recent 2026 scoping review examined randomized controlled trials of in person Reiki that included sham Reiki controls. Only 35 of 154 identified studies met the inclusion criteria. In most of those studies, the sham practitioner followed a Reiki like procedure but lacked Reiki training. The review also found evidence that sham procedures themselves could produce meaningful effects in some studies.
This finding is important.
It means a "placebo" control is not necessarily an inert control.
The person receiving the sham treatment is still receiving attention, time, human interaction, and often physical proximity or touch.
Those experiences can matter.
What Does Placebo Actually Mean?
The word placebo is often used as if it means "imaginary."
That is not a scientifically useful definition.
Placebo related effects can involve expectations, conditioning, context, therapeutic interaction, and other psychological and physiological processes.
If someone feels better after a placebo intervention, that does not mean the experience was fake.
It means the improvement cannot automatically be attributed to the specific biological mechanism proposed by the treatment.
This distinction is especially important for Reiki.
A person may genuinely feel calmer after a session.
A well designed study then asks:
Is that improvement greater than what occurs under an appropriate comparison condition?
The Problem of Blinding
Blinding is easier in a medication trial.
A participant may not know whether they received the active medication or an identical looking placebo.
Reiki is different.
A practitioner knows whether they are practicing Reiki.
A participant may know whether someone is intentionally providing a Reiki session.
This creates opportunities for expectations to influence outcomes.
Researchers therefore have to think carefully about who is blinded, what participants are told, how practitioners are trained, and how treatment conditions are standardized.
Subjective Outcomes Matter
Researchers sometimes favor objective measurements because they appear more scientific.
But that can create another problem.
If the purpose of an intervention includes reducing anxiety, improving perceived well being, or changing pain experience, then subjective outcomes are not inherently inferior.
They are the phenomenon being studied.
The challenge is to measure them rigorously.
Validated questionnaires can help.
Researchers can also pair subjective measures with physiological outcomes.
For example:
How anxious does the participant feel?
What is their heart rate?
What is their HRV?
How do they rate their pain?
What changes occur in their sleep?
Do those changes persist?
Looking at multiple types of outcomes can provide a more complete picture.
Why Reiki Studies Sometimes Disagree
Different Reiki studies may use different:
Treatment durations.
Numbers of sessions.
Practitioner experience levels.
Treatment locations.
Patient populations.
Control conditions.
Outcome measures.
Follow up periods.
Sample sizes.
Statistical methods.
When studies differ substantially in design, it becomes difficult to interpret them as if they were testing the exact same intervention.
This is one reason systematic reviews and meta analyses must be read carefully.
A collection of studies is not automatically strong evidence simply because the number of studies is large.
More Studies Does Not Necessarily Mean Better Evidence
A 2025 scoping review identified 353 clinical studies involving biofield therapies, including 88 Reiki studies. The authors found substantial variation in study design and reporting and concluded that methodological inconsistencies continue to limit conclusions about efficacy.
This illustrates an important principle:
Quantity and quality are different things.
One excellent randomized controlled trial can sometimes be more informative than dozens of poorly designed studies.
Likewise, a large body of heterogeneous research may tell us that something is worth investigating without telling us exactly how effective it is.
What Would a Strong Reiki Study Look Like?
An ideal Reiki trial would begin with a clearly defined research question.
For example:
Does a standardized course of Reiki reduce anxiety in hospitalized adults compared with a credible sham intervention?
The researchers would define:
Who qualifies for the study.
How Reiki will be delivered.
How long each session lasts.
How many sessions participants receive.
Who delivers the intervention.
What the sham condition involves.
What outcomes will be measured.
When outcomes will be measured.
How missing data will be handled.
And what statistical analysis will be performed.
Researchers would ideally preregister their study and report the results regardless of whether the findings are positive.
This is how a field gradually builds trustworthy evidence.
Research Should Be Designed to Find the Truth, Not Confirm a Belief
This may be the most important principle of all.
A Reiki study should be capable of producing a negative result.
If researchers begin with the assumption that Reiki must work, they risk designing studies that unintentionally favor the desired conclusion.
The same is true in the opposite direction.
A researcher who assumes Reiki cannot possibly have meaningful effects may design a study that fails to capture the relevant outcomes.
Good science begins with a question rather than a predetermined answer.
Moving Beyond "Does Reiki Work?"
The question "Does Reiki work?" is actually too broad.
For what?
For whom?
Compared with what?
How much?
For how long?
Measured how?
Under what conditions?
Those questions matter.
An intervention might produce a small but meaningful improvement in one population and no measurable effect in another.
A single session might affect subjective relaxation without producing a lasting clinical change.
A repeated intervention might produce different results.
Some outcomes may be more responsive than others.
The more precise the question becomes, the more useful the answer can be.
The Future of Reiki Research
The future of Reiki research does not need to depend on proving or disproving an entire philosophy of energy.
Researchers can begin with observable questions.
What happens to anxiety?
What happens to pain?
What happens to sleep?
What happens to physiological measures?
What happens to patient experience?
What happens when Reiki is compared with credible sham conditions?
What happens when studies are repeated by independent research teams?
And eventually:
Can we identify biological mechanisms that help explain the observed outcomes?
Those questions move the field forward.
Science and Curiosity Can Coexist
There is a tendency to treat science and spirituality as opposing viewpoints.
They do not have to be.
Science is a method for investigating questions about the observable world.
Reiki is a practice with a long history, a particular philosophy, and a growing body of clinical research.
The scientific study of Reiki does not require practitioners to abandon their traditions.
It requires them to be honest about what is known, what is proposed, and what remains unknown.
That distinction is not a weakness.
It is what makes continued investigation possible.
At Evergreen Reiki, we believe the most valuable question is not:
"How can we prove Reiki works?"
It is:
"What happens when people receive Reiki, under what conditions, for whom, and why?"
That is a question science can continue to investigate.
And it is a question worth asking.
