What Are the Scientific Objections to Hypnosis — And Why Some Experts Still Doubt It

Hypnosis is often praised as a powerful tool for pain relief, anxiety, and habit change — but not everyone in the scientific community is fully convinced. While research shows hypnosis can work for many people, some psychologists and neuroscientists still raise valid questions about how it works, why it works, and whether it works for everyone.

So what are the biggest scientific objections to hypnosis — and why does debate around it still exist today?

1. There’s No Single Definition

One of the biggest challenges is that scientists can’t even agree on exactly what hypnosis is. Is it a special altered state of consciousness? A heightened form of focused attention? Or just social role-playing driven by expectation and suggestibility?

Some researchers argue there’s nothing unique about hypnosis at all — it’s simply a set of instructions that people agree to follow because they trust the hypnotist and want the result.

This lack of a clear, unified definition makes hypnosis hard to study in the same way we study other psychological tools.

2. It’s Hard to Measure

Another objection is that hypnosis can’t be tested with a simple yes or no. Suggestibility varies wildly — about 10–15% of people are highly hypnotizable, but 20% or more barely respond at all.

Even in brain imaging studies, scientists struggle to separate the effects of hypnosis from the effects of deep relaxation or guided meditation. Some skeptics argue that what’s happening in the brain might not be “hypnosis” — just focused relaxation with a new label.

3. It Can Be Highly Suggestible — For Better or Worse

A key strength of hypnosis — that people are more open to suggestion — is also a weakness in the eyes of some experts.

Memory researchers, for example, caution that hypnosis can create false memories. Under deep hypnosis, people may believe what they’re recalling is real — but studies show our brains can easily blend imagination with memory.

This is why reputable therapists rarely use hypnosis to “recover” repressed memories today — the risk of creating unintentional false memories is too high.

4. It’s Not Always Reliable

Another scientific criticism is that hypnosis is far from guaranteed. Some people experience major breakthroughs; others feel nothing at all.

Clinical trials have shown strong results for pain relief and phobias — but mixed results for weight loss, smoking, or stress. And placebo-controlled studies sometimes find hypnosis works better than placebo — but not always dramatically so.

This unpredictability leaves some scientists unconvinced that hypnosis is a reliable stand-alone treatment for everyone.

5. It’s Hard to Standardize

Finally, hypnosis resists standardization. Unlike a medication or surgery that can be replicated exactly, every hypnosis session depends on the skills of the practitioner and the openness of the client.

The same hypnotic script might work wonders for one person and fail completely for another. This makes clinical trials tricky to design and replicate — which slows broader scientific acceptance.

So, Where Does This Leave Us?

Even with these objections, most experts agree on one thing: hypnosis does create measurable changes in the brain, and for many people it can help reduce pain, anxiety, and fear.

But it’s not magic, not mind control, and not a guaranteed fix for everyone. Many researchers see it as a useful tool when combined with evidence-based treatments — not as a stand-alone cure-all.

Bottom line: The scientific debate isn’t whether hypnosis works at all — it’s about how it works, why it works for some people but not others, and how to use it responsibly.