Overview: Explore the science of hypnotherapy and learn how hypnosis works to alleviate stress, end addiction, motivate, and more. 

Does hypnosis work? You might be looking for answers to this questions if you're new to hypnotherapy.

Here's a short answer: Research suggests that hypnosis is a powerful tool for self-improvement. Numerous clinical trials have shown hypnotherapy to be an effective tool for a variety of conditions.

But how does hypnosis work?

Hypnosis is a state of focused awareness and deep relaxation. This state is similar to the state you reach during meditation. During hypnosis, the subconscious is open to new information and suggestions.

Therefore, after we reach this deep, relaxed state, we can begin to change and update the deep beliefs we hold in our subconscious. For example, if you had a negative public speaking experience in grade school, you likely have negative emotions attached to public speaking.

Hypnosis allows us to alter and change these subconscious attachments and beliefs, and there's a growing body of research that suggests hypnosis does work and it's an effective therapy.

How Hypnosis Works to Reshape Our Assumptions?

Let's start with this question: What is hypnosis?

Hypnosis is a highly relaxed mental state. In this state, the mind relaxes and is ready to learn. Hypnosis allows us to turn off the critical, conscious mind. 

In deeply relaxed hypnosis, we can override these automatic thoughts and update this thinking with new suggestions. Hypnosis works by allowing us to alter our unconscious thought processes to achieve specific goals.

Hypnosis In Action: Losing Weight 

Suppose you want to use hypnosis for weight loss. Your subconscious mind has many beliefs about losing weight.

You might automatically think that losing weight is impossible. You may not want to give up sugary snacks, or that you don’t have time for exercise.

Memories, experiences and expectations create and reinforce these unconscious thoughts, which in turn, drive our conscious actions. Often, we don't even realize this is happening.

In short, our subconscious sets us up to fail, and that’s true about many of our bad habits – negative self-talk, smoking, overeating – they’re all deeply rooted in unconscious thought.

Through hypnotherapy, though, we can begin to alter and update these negative assumptions. This process is why hypnosis is effective for a wide range of conditions, from managing chronic pain with hypnosis, to using hypnosis to quit smoking

But why is the subconscious so suggestible under hypnosis? See this clip from the BBC documentary Science of Hypnotherapy to learn more:


How Hypnosis Works: Common Theories 

Hypnosis has fascinated psychologists for centuries.

Beginning in the 1770s, Austrian physician Frances Mesmer – he's where we get the verb mesmerize – first experimented with putting patients into a trance-like state. Mesmer would play ethereal music, dim the lights, and use relaxation techniques.

But Mesmer had some eccentric thoughts about what was happening while in trance. He thought that he was infusing patients with invisible magnetic fluids.

Even though Mesmer was wrong in his assumptions, he did spark our collective curiosity in the field of hypnosis.

Today, there are two main schools of thought regarding what’s going on in the mind while in a state of hypnosis.

State Theory of Hypnosis

The state theory proposes that subjects under hypnosis enter an altered state of consciousness. In this altered state, subjects can disassociate behavioral control from awareness. Subjects can bypass critical conscious thoughts and focus on what they’re doing without asking why.

In an early hypnosis experiment, for example, Ernst Hilgard had subjects hold their hands in a bucket of cold water. Compared to non-hypnotized subjects, those under hypnosis were able to hold their hands in the water for much longer. Ultimately, once the pain became too great, they exited the trance state and removed their hands.

What Hilgard’s experiment showed is that while under hypnosis, the patients were able to bypass that critical thought, e.g. “this water is cold.” This is exactly what the state theory proposes: The state of deep relaxation alters normal brain processes. 

Non-State Theory of Hypnosis

The non-state theory, on the other hand, suggests that hypnotized subjects are playing the role of a person under hypnosis. We have certain conclusions and assumptions of how we’re supposed to act in this role and that influences our behavior during and after a hypnotherapy session.

Therefore, subjects expect or assume they should act a certain way afterwards. For example, we want and expect to quit smoking, and as a result, the therapy is more effective. 

Why Does Hypnosis Work: State Theory

Recent research suggests that the state theory may in fact be correct. Thanks to modern brain imaging technology, research has shown that brain behavior changes when acting on hypnotic suggestions.

Here’s an example:

In 2005, Dr. Amir Raz, a Columbia professor, asked patients to complete a simple task. During the test, participants saw four words written in block letters – GREEN, BLUE, RED, and YELLOW. But the color of ink used for each was incongruent from the written word. For example, BLUE is printed in red ink.

When asked the color of the word BLUE, our brains automatically want to say “blue,” even though the correct answer is red. This is the Stroop Effect, when incongruent ideas are crossed and it takes us longer to answer.

Raz then hypnotized subjects and told them they would see words in gibberish on a screen, and their task would be to identify the color of the ink. Not only did the hypnotized subjects complete the task without delay, but using brain imaging, the area of the brain that decodes written words was not active.

Additionally, recent research has identified the brain changes that happen during hypnosis.

A 2016 Stanford study found that hypnosis draws us into a deep state, in which we're not worrying about anything else. We can turn off outside stimuli. Brain scans also showed connections between brain regions responsible for communicating what is happening in the body, as well as a reduction in someone's ability to be aware of their actions.


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How Hypnosis Changes Learned Thinking Patterns

Raz’s study shows that habitual, learned thinking patterns influence our perception. His subjects expected to read gibberish words, and therefore, the area of the brain that would have normally recognized the word BLUE did not activate.

This idea explains how hypnosis works so effectively.

Our minds have deeply embedded habitual patterning. We develop these thought patterns throughout our lives. Memories, assumptions, negative experiences, positive experiences… They all form and reinforce these patterns and beliefs.

In other words, what we hear, feel, see and assume to be true, isn’t always correct.

Top-Down Processing: Explaining Hypnosis

Our evolving brain networks interpret sensory data and construct our reality.

This is top-down processing. In top-down processing, the information flowing from the top overrides and informs lower-level processes.

Here’s an example: Let's say you see a red car. Visually, your eye captures sensory data about the car. This data is sent to higher brain processing levels, which decode shape and color. Then, this information goes to higher functioning levels where the color and shape help us discern the car’s make and model.

The data flows up, but at the same time, about 10 times the amount of feedback flows down. This top-down feedback tells the brain how to interpret sensory data. Our unconscious thoughts create this feedback. 

This also explains why hypnosis works. We can use suggestions when in the hypnotic state to override the top-down processes with new, more helpful suggestions. 

This allows us to perceive the world through new eyes.

Just look at the Stroop Effect. It’s difficult to say “red” when looking at the word BLUE, because our brains automatically read the word blue before we encode the color of the ink. But when we perceive the words to be gibberish, we’re able to bypass the critical and answer the question without delay.

That’s the key to overcoming bad habits and achieving self-improvement. We must get down to the root cause – our negative assumptions that are keeping the bad habit in place – and override them with better, more helpful information. Therefore, you can overcome your brain’s learned top-down processes – i.e. when you feel stress, you crave sugar – and replace this thinking with a more helpful response.

How Hypnotic Suggestions Work to Alter Preconditioned Beliefs

Our preconditioned beliefs are very strong. In one study, researchers looked at just how strong they are.

In the study, a group of participants took a wine taste test. They had two choices: A glass of “expensive” wine and another of moderately priced wine.

The catch? Both glasses were the same wine.

However, participants expected the expensive wine to taste better, and therefore, they gave it much higher marks for taste.

This study shows the power of suggestion. Suggestions (in this case, that one wine was very expensive) can create our perception.

Bypassing the Critical Mind with Hypnosis

Unfortunately, the critical mind isn't as receptive to suggestion. The critical, conscious mind wants to analyze and critique suggestions.

But with  hypnosis we empower the mind to better accept suggestions? In the deeply  relaxed state of hypnosis, our minds are more susceptible to suggestion.

Suggestion and disassociation allow us to reframe our thinking pattern.

  • Disassociation: While in a state of hypnosis, it's theorized the mind splits into two states, the hypnotized mind and the hidden observer. In other words, we can block out our surroundings and bypass existing top-down thinking (the hidden observer). This empowers us to take suggestion without questioning if the suggestion matches our existing thoughts.
  • Suggestion: During hypnosis, a hypnotherapist directs you to focus on a single idea or suggestion. Since you’ve reached the hypnotized state, you can bypass your critical thoughts regarding the suggestions. Just look at Dr. Raz’s experiment. Hypnosis allows us to act on suggestion without questioning why.

Ultimately, the majority of the time, sensory data matches our top-down processing. We see a red car, and our memories tell us how to interpret and decipher what color the car is.

But hypnosis works by creating a mismatch between bottom-up and top-down thinking.

Through hypnosis, new information trains the mind to respond differently. In effect, we're creating a new reality. We create new, more helpful responses to sensory data. 

Before working with hypnotherapy, when you experience stress, your existing top-down thoughts might trigger you to reach for a cigarette, or binge on sugary foods, or stay awake at night.

Hypnosis allows us to update and reframe these top-down responses and change unwanted behaviors.

Does Hypnosis Work in Clinical Trials?

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In recent years, hypnotherapy has regained popularity in medical fields. In fact, hypnosis is now a common complementary medical service in a number of world-renowned healthcare facilities like The Mayo Clinic.

To date, research paints a compelling picture of hypnosis for a variety of conditions, from addiction, to hypnosis for social anxiety and public speaking.

Here’s a look at some research in a variety of categories:

Insomnia and Sleep Disorders.  A 2010 study found that hypnosis was effective for inducing and increasing slow-wave REM sleep. In the study, subjects who listened to a short sleep hypnosis tape prior to taking a nap achieved 80 percent more slow-wave sleep. (Take a look at our insomnia hypnosis guide for more information.)

Weight Loss. A 1986 study examined how well group hypnosis worked for weight loss. The results: The group that underwent hypnosis lost 17 pounds, while the non-hypnotized group lost just .5 pounds. (Read more about hypnosis for weight  loss.)

Smoking Cessation. A 2008 randomized trial found that smokers who underwent hypnosis were more likely to quit and stay quit than those who received counseling and nicotine replacement therapy. A study in 1994 found that 80% of participants who underwent hypnosis and aversion therapy abstained from smoking after 6 months. (Read more about using hypnosis to quit smoking.)

Substance Abuse.  A study of methadone patients found that those who received hypnosis were much more likely to stay drug-free. Of those receiving hypnosis, 94 percent were narcotic-free at 6 months.

Anxiety and Depression. A 2010 review of research showed six studies that suggested hypnosis helped with anxiety. A 2009 meta-analysis also found that hypnosis was significantly effective for treating depression. (Learn more about hypnosis for anxiety and depression hypnotherapy.)

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A Review: Does Hypnosis Work?

We threw a lot of information at you regarding how hypnosis works. But really, the idea is simple.

Our preconditioned beliefs form our reality. We expect a glass of wine to taste better because it’s more expensive. And we perceive a difference in taste. Our minds interpret real words as gibberish, and we’re able to decipher the color of the ink without delay.

Hypnosis provides a means for overriding our existing beliefs, assumptions and memories. First we follow a hypnotic induction to reach a hypnotized state.

According to the state theory of hypnosis, when we reach hypnosis, we’re able to disassociate our behavioral controls and critical thoughts. In other words, we can hear suggestions and follow them without questioning why we’re following them. Ultimately, it’s the power of suggestion that enables us to reshape and reframe our perceptions.

In other words, our brains have a complex network for interpreting the world around us. Over time, negative and unhelpful automatic thoughts have worked its way into that network. Thusly, when we experience stress, we feel an overwhelming urge to indulge in sweets, or smoke, or turn to drugs or alcohol. We can't control these unconscious urges. They happen automatically.

But hypnosis enables us to overcome and dampen these uncontrolled thoughts. And that’s where the power lies: Hypnosis empowers us to believe suggestions that best serve us to be true. This, in turn, enables us to alter our behavior.

Getting Started with Hypnosis

We offer a number of ways for you to continue exploring hypnotherapy. Try these resources from Grace today:

  • All-in-one hypnosis app Grace – Featuring recorded sessions and series related to anxiety, flight anxiety, performance anxiety and more.
  • Hypnotherapy books – Learn techniques to manage anxiety in CloseYour Eyes, Get Free.
  • Online hypnotherapy sessions – Meet with one of our certified hypnotherapists for one-on-one sessions.