Pink or Blue - Understanding The Placebo Effect


This article takes a deeper look at the placebo effect and studies looking at placebo pills.

As we already talked about in our previous post, a placebo usually refers to a substance or treatment which has no known medical affect effects. The placebo effect describes the phenomenon whereby some people experience a benefit after the administration of the placebo.

That’s right, even though there is no medical reason why someone should experience a benefit, they do.

The placebo effect is fascinating as we can’t really explain it. But it does illustrate the importance of the mind-body when it comes to health. We’ve already gone through the basics of what the placebo effect is; in this article we’re going to look at some fascinating research into this area.

The Pink Pill or Blue Pill ?

For those of you who’ve watched The Matrix, you’re probably getting a flashback of Neo deciding whether to go further down the rabbit hole by taking a red pill. 


Turns out that researchers in the 1970s were way ahead of the game.  Blackwell, Bloomfield & Buncher published a brilliant paper in The Lancet in 1972[1].  They  designed a trial on medical students, future doctors who might one day try to dismiss the effects of placebos. ( As an aside, this experiment adds weight to my theory that psychology researchers from the 1970s had a wicked sense of humour).


Placebo Pills

Each student was given one or two tablets that were either pink or blue. They were told that these were either tranquilizers or stimulants.  Of course they were neither, they were just sugar pills.  Their alertness was measured and they were given questionnaires about what they experienced when they took the pills.

The experiment showed some incredible results:

  • They found that drug associated changes were reported by 30% of the subjects

  • They also found that the blue tablets were associated with more sedative effects than pink capsules.

  • Not only this, but they also found a dose-related effect - two capsules produced more effects than one.

The Effects of Placebo Pills

So let’s recap these results. Some researchers gave a bunch of students some sugar pills but told them they were either stimulants or sedatives. Because of this, nearly a third believed that they had experienced actual effects.

On top of that, the colour of the pills made a difference to what they believed they had been given. 

We traditionally associate blue with feelings of calm and red/pink with feelings of anger and alertness.  Even though the subjects were not told that the sedative was blue and the stimulant pink, they automatically made the association in their minds and this influenced what they thought they felt.  

Not only this, but the study showed that these effects were dose related. Namely that taking two sugar pills had more of an effect than taking just one.


The Placebo Effect in Modern Medicine

The idea of this is mind-boggling.  The study showed that the power of belief is so strong that our brain can trick us into believing we are experiencing actual physical effects from taking sugar pills.  Not only that, but the colour of the pills made a difference.

Pharmaceutical companies use this colour effect today. Many anti-depressant and anti-anxiety tablets come in blue packaging or are blue tablets to help our mind start to believe in what they can do.


The Placebo Effect and Healing

Although this study is from the 1970s, it’s results are still cited in research today. The data on the placebo effect certainly suggests that what we think influences how we physically feel. This is a guiding principle in the emerging field of mind-body medicine.

We’ll be looking at more of the research in upcoming articles. Subscribe to keep upto date.

[1] Blackwell, B., Bloomfield, S., & Buncher, C. R. (1972). Demonstration to medical students of placebo responses and non-drug factors. The Lancet, 299(7763), 1279-1282