Clinical Research Glossary

placebo placebo


Something that looks like the treatment being studied, but doesn't contain any medicine 

Example of placebo in a sentence

Using a placebo in a research study keeps the participant and study doctor from knowing who is receiving the active treatment.

More Info

A placebo is made to look, taste and smell like the active treatment being studied. Depending on the study, a placebo can also refer to a device or sham surgery. A placebo helps the researcher see whether the active study treatment really works. Using a placebo reduces bias.

Using a placebo in a research study is accepted when the risk of not treating a condition is small or when there is no effective standard of care to compare to.

Other info to think about when joining a study

When describing the plan of the study, the study team or consent form will say whether or not a placebo is being used in the study. When a placebo is included in a study, the participants will usually be assigned the placebo through “randomization.” This means that whether or not you get the placebo will happen by chance, like flipping a coin.

You should feel free to ask if there is a chance you could be taking a placebo in the study. You can also ask if you will find out if you are on the placebo at the end of the study. It may also be important for you to ask how they will notify your regular doctors if you are on the placebo or taking an active study treatment if there is a medical need to know.

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