Word of the Week: Placebo

Each week, Verywell explains a term from health, medicine, science, or technology.

Placebo

How to say it: Placebo (plah-SEE-bow)

What it means: A treatment or substance with no real medicine in it.

Where it comes from: From Latin, placebo, "I shall please"

Where you might see or hear it: When researchers are testing a new treatment, they need to compare it to something to see how well it works. One way they can do this is by giving one group of people the real treatment and giving the other group a treatment that looks real but is not.

One example is testing a medication. The researchers can put people in the study into two groups. Both groups are told that they are getting medication. One group gets the real medication and the other group gets a pill that looks exactly like the real medication but it's actually just made of sugar and has no real medicine in it.

The researchers will see if the people who took the real medicine felt better than the people who took the placebo.

When you might want to use it: You've probably heard about "the placebo effect." For example, say that you were given a pill to help your headaches. You took the pill and felt better.

However, let's say that you were part of an experiment. You actually took a pill that was just made of sugar. There was no headache medicine in it. The fact that you felt better even though you didn't take any medicine could be called the placebo effect.

On the other hand, people can also experience the "nocebo" effect. In this case, let's say you were given a pill for your headache and told that it could cause you to feel dizzy. When you took the pill, it made you feel dizzy, so you didn't take it again.

Let's say that you were part of an experiment and in fact, you took a placebo pill with no medicine in it. However, you still experienced side effects of the real medicine even though you did not take any real medicine.