Acetaminophen vs Ibuprofen: what is the difference?
Ibuprofen is an NSAID that eases inflammation as well as pain, while acetaminophen acts mainly in the central nervous system and does little for inflammation.
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; 14 atoms differ, too many to mark as one group.
Side by side
| Acetaminophen | Ibuprofen | |
|---|---|---|
| Molecular weightCalculated PubChem | 151.16 g/molC8H9NO2 | 206.28 g/molC13H18O2 |
| Hydrogen-bond donorsCalculated PubChem | 2 | 1 |
| Half-life in the bodyEditorial MoleculeFinder curated | about 2 h | about 2 h |
| Where each turns upEditorial MoleculeFinder food and product lists |
|
|
| Also sold asEditorial MoleculeFinder curated | Tylenol | Advil, Motrin, Nurofen |
| FamilyEditorial MoleculeFinder curated | Over-the-counter medicines, 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) | Aromatics, Amides, Phenols | Carboxylic Acids, Aromatics |
| Hazard labelReported ECHA, HSDB via PubChem; ECHA via PubChem | Warning | Warning |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | 2,400 mg/kgpure acetaminophen, rat, oral | 636 mg/kgpure ibuprofen, rat, oral |
| A single acute animal measure. 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, HSDB via PubChem; ECHA via PubChem
- Oral LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Identifiersfrom sourcePubChemPubChem CID 1983 (Acetaminophen) and 3672 (Ibuprofen).
In more detail
Both are sold over the counter for pain and fever, as Tylenol and Advil, and they are not the same kind of drug. Ibuprofen is an NSAID: it blocks the COX enzymes throughout the body, which is why it reduces inflammation and swelling as well as pain. Acetaminophen, called paracetamol outside the US, acts mainly in the central nervous system and does very little for inflammation, which is why a sprain and a headache are not the same problem for it. The functional groups in the table show the split, ibuprofen carrying a carboxylic acid and acetaminophen an amide and a phenol. Their reported oral LD50 values differ by a factor of nearly four, 2400 mg/kg in rats for acetaminophen against 636 mg/kg for ibuprofen, though the risks that actually matter for each are organ specific rather than a matter of the headline number.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Acetaminophen and Ibuprofen?
- Ibuprofen is an NSAID that eases inflammation as well as pain, while acetaminophen acts mainly in the central nervous system and does little for inflammation.
- Is Acetaminophen bigger than Ibuprofen?
- Ibuprofen is the heavier molecule, 206.28 g/mol against 151.16 g/mol for Acetaminophen. Acetaminophen is C8H9NO2 and Ibuprofen is C13H18O2.
- Which has the lower reported LD50, Acetaminophen or Ibuprofen?
- Ibuprofen, at 636 mg/kg (oral, rat), against 2,400 mg/kg (oral, rat) for Acetaminophen. 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.