The Amazing Power of the Placebo

placebo pills

image: iStock photo


Nearly everyone has experienced a placebo effect!

The fact that you take a medicine tells me that on some level you must believe in it or expect it to work, or you believe in the doctor who prescribed it, or even in the improvement you’ve heard about in other people.

This belief, or expectation, activates the placebo effect. Of course, the drug works too but your mind can enhance it….. or suppress it.

The same placebo can do opposite things, for instance, depending on what the person believes it is for. If patients are given a placebo and told it will relax their muscles then it will, but the same placebo can cause muscular tension if the person believes that’s what it does. Similarly, believing that it is a stimulant will increase heart rate and blood pressure, but thinking that it is a depressant gives it the opposite effect – reducing heart rate and blood pressure.

Some people who are given alcohol placebos, thinking they are drinking real alcoholic beverages, even get drunk.

And placebos can enhance athletic performance. In a 2007 study, non-professional athletes had been given morphine during a pre-competition training phase. On the day of a competition the morphine was secretly swapped for a placebo but the athletes still experienced an increase in pain endurance and physical performance that would be expected from taking morphine.

I wonder if they would have been banned from competition if they’d been caught taking performance enhancing placebos (PEP). As an ex-athletics coach myself, all athletes really need is a PEP talk! 🙂

In another study, 40 asthmatics were given an inhaler containing a placebo that was just water vapour, but they were told that it contained allergens that would restrict their airways. Nineteen of them went on to suffer considerable constriction of their airways. Twelve of them actually experienced a full-blown asthma attack. When they were given a different inhaler and told it would relieve their symptoms, it did, even though it was also a placebo. One person in the study developed symptoms of hay fever too after being told that the inhaler also contained pollen.

Colour can matter with placebos, because of what the colour represents to us. A University of Cincinnati study tested both blue and pink stimulants and sedatives on students, although unbeknownst to the students the stimulants and sedatives were placebos.

But the blue placebo sedatives were 66% effective, compared with 26% for the pink ones. Blue placebos were around 2.5 times more effective for relaxation that pink ones. This is because blue is generally considered to be a calming colour.

Where you live also affects the power of placebos. In a US study of migraine treatments, placebo injections were 1.5 times more powerful than placebo pills. But a European trial found that placebo pills were about 10% better than placebo injections. The reason for the difference? It’s in our cultural language. US patients tend to speak of ‘getting a shot’ so they believe in it more, but Europeans talk of ‘popping pills’, or at least they do in the UK.

On a kind of similar note, in trials of Tagamet, the anti-ulcer drug that was popular in the 80s, the placebo was 59% effective in France but the drug itself was 60% effective in Brazil – a difference of 1%. The placebo in one country was as good as the drug in another!

Studies like these strongly hint that we have far more ability to affect our health through our thinking than we might have believed in the past.

How a placebo is packaged and sold also makes a difference to its power. In a UK study, 835 women were given one of four different pills for headaches. One group received a well-known branded aspirin tablet. A second group received a simple tablet labelled ‘analgesic’, which was typical of a cheaper mass-market brand. A third group received a branded placebo, while the last group received a basic ‘mass-market’ placebo labelled ‘analgesic’.

It turned out that the branded aspirin worked better than the unbranded one, but amazingly the branded placebo worked better than the unbranded placebo – even though they were both made of sugar.

The placebo effect might even lift the power of Viagra beyond its basic pharmacological effect, at least according to psychiatrist Aaron K. Vallance, who suggested in a 2006 paper that the medicine might be enhanced because the name ‘Viagra’ is similar-sounding to the words, ‘vigour’ and ‘Niagara’. This might create a perception of vigorousness and power. I wonder if it would work so well if it was called ‘Flopsy’! 🙂

Of course, the drug works extremely well. Drugs are built to carry out biological functions in the body. I know this for a fact. My PhD was in building molecules, or organic chemistry as it’s officially known, and I spent 4 years in cardiovascular and cancer drug development in the pharmaceutical industry. But there is no question that the mind impacts the body. Imagining something, for instance, can even physically impact brain structure.

The challenge is in tapping into this latent power within us. Doctors can help or hinder, even when they don’t know they are doing it.

We know this because some of the variation in placebo effects simply comes down to the communication between medical staff and patient. For relatively common ailments at least, a doctor or physician who shows confidence or optimism about the patient’s recovery is much more likely to see the patient recovering than one who is unsure or pessimistic.

What is said and, importantly, how it is said can make a big bit of difference. But ultimately, it’s what then goes on in the patient’s mind that leads to the health-giving effects.

I personally believe that we have far more ability to affect our health and, dare I say, to heal ourselves, than we have ever thought possible. The question is how to tap into this ability.

I believe we can make a start by doing something active with our minds and believing in it. This is why I explain the science of how the mind impacts in the body in my talks and books – so that people can understand how their thinking affects their health. That way, when they apply visualization strategies, they tend to believe in themselves, and in so doing they are tapping into this ability.

Of course, this is not to be done instead of medical advice, but in addition to it. That is just being intelligent. We might as well get the best of everything.

And that includes the best use of the mind too!!

Further Reading

David R Hamilton PhD, How Your Mind Can Heal Your Body – For examples and explanation of the placebo effect, other mind-body phenomena, and various visualization strategies for different ailments. UK paperbackUS paperback,  UK Kindle,  US Kindle

Daniel Moerman, Meaning, Medicine, and the Placebo Effect – for heaps of research on the placebo effect. UK paperbackUS paperback

How Your Mind Can Heal Your Body – UK & Ireland Speaking Tour

In these workshops, I’ll share all the ways that the mind impacts the body, from the placebo effect, to how meditation impacts the brain, to how attitude affects the heart and ageing, even to how visualisation can physically impact brain structure. You’ll also learn how people around the world have used mind-body interventions (visualisation strategies) to help facilitate recovery from illness and disease, learn the principles involved, and learn and practice a few visualisation techniques.


GLASGOW – 22nd March 2014

LONDON – 29th March

NORWICH – 5th April

KINROSS – 6th April

DUBLIN – 12th April

MANCHESTER – 26th April


US dates to follow … will be announced on my newsletter

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  1. David Malfesi on February 18, 2014 at 10:07 am

    My wife and I saw the Horizon documentary last night. And whilst we both enjoyed the show, each of us actually felt more knowledgable than the programme makers; all due to you sharing your thoughts and research on this subject. We had the good fortune of attending one of your talks a while ago. This was a small venue in Nottingham where you held us enthralled. The placebo effect has become one of our favourite topics of conversation, and it amazes us how many people refer to this as ‘oh, it’s ‘just’ the placebo effect’; almost as though this is something to be embarrassed about! An exciting and thoroughly fascinating subject. We were a little disappointed not to see you on Horizon last night but did wonder whether you were watching it……..

    • David R. Hamilton PhD on February 18, 2014 at 11:11 am

      Thanks David. Oh, I remember that talk very well. It was my first (and only, so far) talk in Nottingham. 🙂 Thanks for your kind words. I enjoyed program very much. I particularly enjoyed seeing the evidence presented that expectation and belief actually does produce measurable changes in brain chemistry. I think that alone will demonstrate to anyone skeptical of the mind-body connection, who dismisses the subject as ‘just the placebo effect’ (as many did when I worked as a scientist in the pharmaceutical industry), that there is a lot more to the mind-body connection that we tend to normally think. 🙂

  2. Alan Taylor on February 18, 2014 at 10:34 am

    Hi David, just a quick comment on last nights tv prog.
    I thought it was ‘slanted’ towards the medical/pharmaceutical industry where the way the narration used words such as the ‘power of placebo’ as if it were a medical/scientific discovery. It was 38 mins. into the prog before the word ‘expectation’ was used.
    There was no acknowledgement of the power of belief- which implies the power of the individual. That’s my take on it.
    However , it’s great to even see such a prog on TV.
    I love your work David. It’s in line with my own. Hope to meet you one day. Peace

    • David R. Hamilton PhD on February 18, 2014 at 11:08 am

      Hi Alan, I hadn’t thought about that. I loved the documentary. It has stimulated a lot of debate and brought the issue more into mainstream. I think the BBC tend to ensure they are being very academic, especially with Horizon, so I can understand why they might and, in fact, have do this. I was originally set to present a Channel 4 feature on placebo (in 2012/13), but it was pulled after the commissioning producer moved to the BBC. I would, perhaps, have been a bit more liberal, and indeed positively suggestive, in my choice of language. 🙂

  3. Denise on February 18, 2014 at 10:47 am

    Fantastic article David.

    Denise x

    • David R. Hamilton PhD on February 18, 2014 at 11:02 am

      Thanks Denise. 🙂

  4. Hussain Fahmy on February 18, 2014 at 10:51 am

    When the brain thinks that we really are healing. It then changes as if healing is happening, and this stimulates the actual area of the body that we are imaging at the cellular level. Be convinced that this causes cellular and genetic changes at that site, which eventually leads to what we are imagining happening (a healed body) actually happening.

  5. Jan Barton on February 18, 2014 at 12:00 pm

    Thanks for this great article David. I saw you in Exeter in the beautiful St David’s church venue. Will you ever come down our way again????? Would love to see you talk again.

    • David R. Hamilton PhD on February 21, 2014 at 12:15 pm

      Thanks for the vote on confidence in me Jan. 🙂 I have nothing in my schedule at the moment, but I may find myself there sometime this year. 🙂

  6. Nanci George on February 18, 2014 at 12:18 pm

    Haven been a nurse for over 30 years, I appreciated the attention to not only what the “patient” believes, but what the medical staff are telling them. This continues to remind me to pay attention to my thoughts, and the words I speak.
    Thank you! I thoroughly enjoy your work!

    • David R. Hamilton PhD on February 21, 2014 at 12:14 pm

      Thanks Nanci. Yes, a huge part of the placebo effect is how medical staff communicate. Like you, I try to be quite mindful of my words, choosing carefully when I feel I can help. 🙂

  7. Maria Espley on February 18, 2014 at 10:00 pm

    Hi David..did not see documentary last night…however …I remember years ago…I was in charge of the High Dependancy Unit our local hospital…we had an admission of a nurse that worked at the same hospital as myself…she had been stealing strong analgesics and injecting herself…and had now had a huge meltdown..she was to be referred to the physiatrist the following day….the duty doctor had written her up for….aqueous fluid…I/m. As requires!…I told her I was going to give her the same drug she had been stealing…that I was also going to give her double the amount to ensure a good nights sleep..she loved the idea!! The following morning she asked if I would be on duty that night…as she needed me to give her the same again…and she trusted nobody else to give the amount I had.. She told me it was the best night sleep she had had in months!…. Poor woman but yes the power of the mind is astonishing!!!….hope to get to see you at Manchester.,

    • David R. Hamilton PhD on February 21, 2014 at 12:12 pm

      Thanks for sharing that Maria. Yes, the power of the mind is quite astonishing. 🙂