Ibuprofen vs Naproxen: what is the difference?
Ibuprofen and naproxen are both NSAIDs, but naproxen lasts far longer, with a half-life near 14 hours against about 2 for ibuprofen.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Drawn the same way round on the skeleton they share. Aligned; 10 atoms differ, too many to mark as one group.
- Structural similaritycomputedRDKit Morgan/Tanimoto0.42 of 1, a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.
Side by side
| Ibuprofen | Naproxen | |
|---|---|---|
| Molecular weightCalculated PubChem | 206.28 g/molC13H18O2 | 230.26 g/molC14H14O3 |
| Hydrogen-bond donorsCalculated PubChem | 1 | 1 |
| Half-life in the bodyEditorial MoleculeFinder curated | about 2 h | about 14 h |
| Where each turns upEditorial MoleculeFinder food and product lists |
| Not on our lists |
| Also sold asEditorial MoleculeFinder curated | Advil, Motrin, Nurofen | Aleve |
| FamilyEditorial MoleculeFinder curated | Over-the-counter medicines, NSAIDs, Non-opioid painkillers | Over-the-counter medicines, NSAIDs, Non-opioid painkillers |
| Everyday groupEditorial MoleculeFinder curated | OTC medicine | OTC medicine |
| Chemical groupsCalculated Found by rule (RDKit) | Carboxylic Acids, Aromatics | Carboxylic Acids, Aromatics, Ethers |
| Hazard labelReported ECHA via PubChem | Warning | Danger |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | 636 mg/kgpure ibuprofen, rat, oral | 1,234 mg/kgpure naproxen, mouse, oral |
| A single acute animal measure, here in two different species. It ranks nothing about human safety. | ||
Sources and notes
- Molecular weightcomputedPubChemComputed from the structure; the formula is under each weight.
- Hydrogen-bond donorscomputedPubChemThe hydrogens on nitrogen or oxygen that each molecule can lend to a hydrogen bond, counted from its structure.
- Half-life in the bodyfrom sourceMoleculeFinder curatedIn a typical adult: the time the body takes to clear half of it.
- Where each turns upfrom sourceMoleculeFinder food and product listsEach amount is an editorial figure from our lists, not a measurement of any one product. Each mark is set by hand on the list, never inferred.
- Also sold asfrom sourceMoleculeFinder curated
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Chemical groupscomputedFound by rule (RDKit)Each group is found in the structure by a chemical pattern.
- Hazard labelfrom sourceECHA via PubChem
- Oral LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Identifiersfrom sourcePubChemPubChem CID 3672 (Ibuprofen) and 156391 (Naproxen).
In more detail
These are the closest pair on the OTC shelf: both propionic acid derivatives, both blocking COX. The practical difference is time. Ibuprofen has a half-life near 2 hours and naproxen near 14, which is why one is taken through the day and the other is sold as a twice-daily tablet under the name Aleve. Naproxen is the heavier molecule at 230.26 against 206.28 and carries an extra ether group on a naphthalene ring rather than ibuprofen's simple benzene. Reported oral LD50 sits at 636 mg/kg in rats for ibuprofen and 1234 mg/kg in mice for naproxen, measured in different species, so the two numbers are not directly comparable.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Ibuprofen and Naproxen?
- Ibuprofen and naproxen are both NSAIDs, but naproxen lasts far longer, with a half-life near 14 hours against about 2 for ibuprofen.
- Is Ibuprofen bigger than Naproxen?
- Naproxen is the heavier molecule, 230.26 g/mol against 206.28 g/mol for Ibuprofen. Ibuprofen is C13H18O2 and Naproxen is C14H14O3.
- Which has the lower reported LD50, Ibuprofen or Naproxen?
- Ibuprofen, at 636 mg/kg (oral, rat), against 1,234 mg/kg (oral, mouse) for Naproxen. An LD50 is one acute animal measurement, and the two here were not necessarily measured in the same species, so it is a data point rather than a ranking of how dangerous either is to a person.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.