SHEET /m/naproxen · PubChem CID 156391 · CAS 22204-53-1 · REV 2026.07
Naproxen
from sourceC14H14O3 · 230.26 g/mol
Equiproxen · Naixan · Nycopren
Also sold as Aleve from source
What is Naproxen?
A longer-acting anti-inflammatory painkiller sold as Aleve, used for pain, fever, and inflammation. Naproxen (C14H14O3, 230 g/mol) is an over-the-counter medicine sold over the counter. from source
Fig. 1 · 2D structure RDKit
C[C@@H](C1=CC2=C(C=C1)C=C(C=C2)OC)C(=O)OWhere you'll find it
Sold over the counter, without a prescription. Sold as Aleve. See the rest of the otc medicine group.
Still in the system computed
For a typical adult, Naproxen clears on a half-life of about 14 h: every 14 hours, half of what is left is gone. Try an amount:
An illustration of half-life, not a prediction of anyone's level.
Relative acute toxicity from source
Animal study data · LD50
- Reported LD50
- 1,234 mg/kg · low toxicity
- Species
- mouse
- Route
- oral
An LD50 describes acute toxicity under experimental conditions and is not a safe or dangerous dose for a person.
Signature properties
Toxicity & hazards
Toxicity · LD50
1,234 mg/kg · low toxicity · LD50 mouse oral from source
3 more reported values
- 435 mg/kgLD50 · iv · mouse
- 475 mg/kgLD50 · other · mouse
- 500 mg/kgLD50 · other · mouse
Keep roaming
Where Naproxen leads
Compare with
Naproxen is the long-acting NSAID: chemically close to ibuprofen but cleared far more slowly, with a half-life near fourteen hours. One dose lasts most of a day, and it lingers long after the pain is gone.