Medicines and prescriptions
What Are Inactive Ingredients in a Medicine?
Inactive ingredients · say it: in-AK-tiv in-GREE-dee-untsAlso written: excipients, other ingredients, inert ingredients, fillers
Short answer
Inactive ingredients are the parts of a medicine that are not the drug itself, such as fillers, colours, coatings and preservatives.
What it means
Every tablet, liquid or cream contains the active ingredient, which does the medical work, and inactive ingredients, also called excipients. These help hold a tablet together, make it easier to swallow, protect it, add colour or flavour, control how fast it dissolves or keep a liquid from spoiling. Examples include lactose, starch, gelatin, dyes, sugar, alcohol and preservatives.
Labels list them because, although they do not treat anything, some people react to them or need to avoid them. Examples are lactose in severe lactose intolerance, gelatin for dietary or religious reasons, gluten for coeliac disease, certain dyes, sugar in diabetes, alcohol in some liquids, and aspartame (a source of phenylalanine) for people with phenylketonuria. Generic and brand versions of the same medicine can have different inactive ingredients.
'Inactive' means it does not treat the condition, not that it can never cause a reaction.
Where you may see it
- The 'Inactive ingredients' line at the bottom of the US Drug Facts panel
- The 'Contents of the pack and other information' section of leaflets
- Prescribing information under 'Description'
📄 How it looks on a report
Inactive ingredients: corn starch, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, titanium dioxide.
🙅 What it does not mean
- 'Inactive' does not mean nobody can react to it.
- Two versions of the same medicine do not always have the same inactive ingredients.
- It does not mean the product is weaker or of lower quality.
🎯 Check yourself
Which of these is the right meaning of “Inactive ingredients”?
🗒️ Questions to ask your doctor
🧾 Reports where you will see “Inactive ingredients”
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💊 Medicines whose labels mention “Inactive ingredients”
Plain-English explanations of each medicine, from its official FDA label.
- Acetaminophen
A pain reliever and fever reducer
- Allopurinol
a xanthine oxidase inhibitor, a prescription medicine that acts on uric acid
- Amlodipine
a calcium channel blocker, a type of medicine that relaxes blood vessels
- Citalopram
a selective serotonin reuptake inhibitor (SSRI), a type of antidepressant medicine
- Clonazepam
a benzodiazepine, a type of medicine that slows activity in the central nervous system
- Gabapentin
An antiepileptic (seizure) medicine. The label also describes it as a treatment for nerve pain after shingles.
- Levothyroxine Sodium
a synthetic thyroid hormone (L-thyroxine, also called T4), described on the label as chemically identical to the hormone made by the human thyroid gland
- Loperamide
a synthetic antidiarrheal medicine
- Risperidone
an atypical antipsychotic medicine
- Rosuvastatin
a cholesterol-lowering medicine of the statin type (an HMG CoA reductase inhibitor)
🔗 Read more from trusted sources
- “Inactive ingredients” on MedlinePlus ↗
US National Library of Medicine
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