Ibuprofen is a monocarboxylic acid that is propionic acid in which one of the hydrogens at position 2 is substituted by a 4-(2-methylpropyl)phenyl group.
Definition
US FDA substance register · UNII WK2XYI10QM · registered name Ibuprofen · single chemical substance
Ibuprofen is a monocarboxylic acid that is propionic acid in which one of the hydrogens at position 2 is substituted by a 4-(2-methylpropyl)phenyl group. It has a role as a geroprotector, a non-steroidal anti-inflammatory drug, a non-narcotic analgesic, an antipyretic, a xenobiotic, a radical scavenger, a cyclooxygenase 2 inhibitor, a cyclooxygenase 1 inhibitor, an environmental contaminant and a drug allergen. It is functionally related to a propionic acid. It is a conjugate acid of an ibuprofen(1-).
Source: PubChem
Cosmetic roles
Safety & regulatory references
Not classified under Korea’s toxic-substance GHS list · existing chemical substance
Other restriction: ban substances that deplete the ozone layer
Source: EU CosIng ingredient list
More data — names, identifiers, properties, test records, literature
Names & identifiers
- CAS No.chemical registry number
- 15687-27-1
- EC No.EU chemical inventory number
- 239-784-6
- DTXSIDUS EPA chemical ID
- DTXSID5020732
- DTXCIDUS EPA compound ID
- DTXCID90732
- IUPAC
- 2-[4-(2-Methylpropyl)phenyl]propanoic acid
- Molecular formula
- C13H18O2
- Molecular weight
- 206.285 g/mol
Measured properties
- Appearance
- Other Solid · Solid
- Odour
- Characteristic odor
- Boiling point
- 157 ºC
- Melting point
- 75-77.5 ºC · 75-77 °C
- Solubility
- 21 mg/L (at 25 °C) · Readily sol in most org solvents
- Stability
- STABLE
- Dissociation constant
- 4.45 · 5.3
Values measured on the substance itself, not a specification for a commercial raw material.
Source: PubChem
What products actually use it for
What the 6 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.
- Pharmaceutical (EPA)5
- Softener and conditioner1
Source: US EPA CompTox dashboard
Irritation and sensitisation studies
4 skin studies and 1 eye studies are on record.
The study conclusions largely agree (100%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.
See all 5 studies
- Classification not possible
Skin Sensitization · Screening - Classification not possible
Skin Irritation · Screening - Not likely to be sensitizing
skin sensitisation: in vivo (non-LLNA) · Screening · according to OECD Guideline 406 (Skin Sensitisation) (1981) - SkinIrr2
Skin Irritation · QSAR Predicted - Classification not possible
Eye Irritation · Screening
Source: US EPA CompTox dashboard
Related literature
- Comparative evaluation of ibuprofen and ibuprofen sodium nano micelles loaded dissolving microneedles in healthy human volunteers. · 2025
- Evaluation of the Structural Modification of Ibuprofen on the Penetration Release of Ibuprofen from a Drug-in-Adhesive Matrix Type Transdermal Patch · 2022
- Comparison of diclofenac gel, ibuprofen gel, and ibuprofen gel with levomenthol for the topical treatment of pain associated with musculoskeletal injuries · 2019
- Characterization of Patients with Ibuprofen Hypersensitivity · 2018
- Pelepasan Ibuprofen dari Gel Karbomer 940 Kokristal Ibuprofen-Nikotinamida · 2015
Linked databases 17
- Australian Industrial Chemicals Inventory (AICIS)
- ChEBI
- ChEMBL
- EU CosIng ingredient list 2
- Korea Cosmetic Association ingredient dictionary
- Korea toxic substances GHS register (NIER)
- MFDS (Korea) cosmetic ingredient register 2
- NIST Chemistry WebBook
- PubChem 2
- Tlooto literature search 2 3 4 5
- UniChem cross-reference IDs
- US EPA CompTox dashboard 2
- US EPA DSSTox chemical database
- US FDA substance registration (GSRS)
- US FDA Unique Ingredient Identifier (UNII)
- Wikidata
- Wikipedia · Korean · English · Japanese · Chinese