Medicines and prescriptions
What Is a Placebo? Why Medicine Labels Mention It
Placebo · say it: pluh-SEE-bohAlso written: sugar pill, dummy pill, placebo-controlled
Short answer
A placebo is a dummy treatment with no active medicine, used in studies to compare against the real medicine.
What it means
A placebo looks like a real medicine, such as a tablet or injection, but has no active ingredient. In clinical trials, some people get the real medicine and others get a placebo, usually without knowing which. Comparing the two groups shows which effects come from the medicine itself.
Medicine labels mention placebo in tables of side effects and results, for example 'headache: drug 10%, placebo 8%'. This helps you see which side effects are likely caused by the medicine and which also happen in people taking a dummy pill. If a side effect is about as common with placebo, the medicine may not be the cause.
The 'placebo effect' is when people feel better, or notice side effects (sometimes called a nocebo effect), just from expecting it. It is a real effect on how people feel, but it does not mean the medicine is fake.
Where you may see it
- Side effect tables in prescribing information
- 'Clinical studies' sections of medicine labels
- Clinical trial consent forms
📄 How it looks on a report
In placebo-controlled trials, the most common adverse reactions were nausea and headache.
🙅 What it does not mean
- A side effect listed in a placebo trial is not always caused by the medicine; compare the two columns.
- Your doctor is not secretly giving you a placebo when you get a prescription.
- The placebo effect does not mean your symptoms are imaginary.
🗒️ Questions to ask your doctor
🧾 Reports where you will see “Placebo”
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💊 Medicines whose labels mention “Placebo”
Plain-English explanations of each medicine, from its official FDA label.
- Cetirizine
an antihistamine of the selective H1-receptor antagonist type
- Clindamycin Phosphate
A lincosamide antibacterial medicine
- Estradiol
An estrogen hormone medicine
- Fluticasone Propionate
A corticosteroid, which is a steroid medicine, given as a nasal spray
- Lamivudine
An antiviral medicine of the nucleoside analogue reverse transcriptase inhibitor type, used here for hepatitis B
- Olanzapine
An atypical antipsychotic, a prescription medicine used for certain mental health conditions
- Risperidone
an atypical antipsychotic medicine
- Tamsulosin
An alpha-blocker medicine. The label calls it an alpha 1 adrenoceptor antagonist that acts on the prostate. The FDA class is not listed.
- Venlafaxine
An antidepressant. The label's patient information describes it as a serotonin and norepinephrine reuptake inhibitor (SNRI).
🔗 Read more from trusted sources
- “Placebo” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “placebo”
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