US Medical Term · medicines
Placebo
Placebo
In 9 languages
| Language | Term |
|---|---|
| English | Placebo |
| Spanish (Español) | Placebo |
| Chinese (中文) | 安慰剂 |
| Korean (한국어) | 위약 |
| Vietnamese (Tiếng Việt) | Giả dược |
| Filipino (Tagalog) | Placebo |
| Portuguese (Português) | Placebo |
| Thai (ภาษาไทย) | ยาหลอก |
| Japanese (日本語) | プラセボ（偽薬） |
What it means
A placebo is an inactive substance, device, or procedure used in clinical trials as a comparison to the experimental treatment. Participants may receive either the real treatment or a placebo without knowing which they received — this is called blinding. The placebo effect refers to real physiological improvements some patients experience even when receiving an inactive treatment, due to expectation and belief. Placebos are critical to rigorous clinical research design. Outside of trials, providing placebos without disclosure to patients raises ethical concerns.
How to say it
Sentences a patient might use with a doctor, nurse, pharmacist, or insurer:
In the clinical trial, half the participants received the new drug and half received a placebo.
En el ensayo clínico, la mitad de los participantes recibieron el nuevo medicamento y la otra mitad recibieron un placebo.
I want to make sure I understand whether I might receive a placebo in this study.
Quiero asegurarme de entender si podría recibir un placebo en este estudio.
The placebo group showed no improvement, which confirmed that the drug was effective.
El grupo de placebo no mostró mejoría, lo que confirmó que el medicamento era efectivo.
Where you'll see it
Related terms
Related guide
→ US Guide: clinical trials and how research studies workSources
Last reviewed: September 2026