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Drugs & Health Blog

Say What? “Placebo”

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The NIDA Blog Team

"Say What?" is a periodic series in which we define scientific terms and explain their importance.

Why would a researcher give someone a pill when the researcher knows the pill will have no effect on that person? Sounds pointless, right? But there can be an important reason.

Before a drug is approved to treat a health condition, it’s tested many times to be sure it works and is safe to use. During these tests, a researcher often uses a placebo. A placebo looks like a real drug (a pill, for instance), but unlike a real drug, it doesn’t contain active ingredients. In fact, a placebo pill might be made of sugar.

Which one’s real?

So, how do scientists use a placebo? Consider this scenario: A scientist wants to test how well a medication helps someone quit smoking. To figure that out, they’ll set up a study and randomly assign some people to take the real drug and others to take a placebo. Only the scientist knows who’s getting the real drug. And sometimes, even the scientist doesn’t know; this is called a “double-blind” study.

The scientist then compares how both groups reacted to the pills. If there’s no difference, the drug probably didn’t work the way it was supposed to. If there is a difference (and depending on several other factors), it may justify further study.

“Placebo effect”

Sometimes a person will seem to be affected by a placebo. The term “placebo effect” refers to a positive response someone feels after they take a placebo, simply because they expect to feel something when they take a pill. Pretty interesting, huh?

Placebos are used in all types of studies, including ones about treating addiction and developing medications for opioid use disorder. So, that’s how a pill that causes no effects can make a big difference.

Learn about another important part of scientific research: data.

Comments posted to the Drugs & Health Blog are from the general public and may contain inaccurate information. They do not represent the views of NIDA or any other federal government entity.


Knowing the Placebo effect means that we understand a pattern or a fact that always comes out as true. This might be important to me because I would able to tell when one of my friends is on a drug based on their behavior if it's the same pattern as described. I can use this in the future to stay safe from drugs and I will be able to tell when someone is on a drug.
I think that it is crazy that a Placebo drug can actually help someone that is in pain or needs more confort due to pain. But why do we still have to give out medicin to help people when this sometimes works just as good.
I have heard how the placebo effect works and I find it interesting how effective it is when being used.
How do you know that drug effect is also not placebo effect?

Great question! Before a drug is approved to treat a health condition, it’s tested many times to be sure it works. If a scientist compares the real drug to the placebo and sees no difference, the drug probably didn’t work the way it was supposed to.

We understand how hard it can be to see a loved one struggling with a possible drug problem. While we can’t offer medical advice, we do recommend consulting with a health care provider to ask for assistance specific to your geographic area and your brother’s needs and willingness to get help. You’re also doing him a great service by continuing to ask questions and listen when he’s ready to talk. You might also consider calling the Substance Abuse and Mental Health Services Administration's National Helpline at 1-800-662-HELP (4357) for treatment referral and information, 24/7.

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