Caffeine
Properties
- Molecular formula
- C8H10N4O2
- Molar mass
- 194.19 g/mol
- Exact mass
- 194.0804 Da
- Density
- 1.23 g/mL (at 18 °C)
- Melting point
- 238 °C
- pKa
- 0.7 (caffeine cation), 10.4 (tertiary amine, 40 °C), 14 (25 °C)
- Water solubility
- 21.7 g/L
- logP
- -1.03Crippen estimate
- Polar surface area
- 61.8 Ų
- H-bond donors / acceptors
- 0 / 3
- Rotatable bonds
- 0
The world's most-consumed psychoactive compound - a methylxanthine adenosine-receptor antagonist found in coffee, tea, and cocoa. Zhang et al. (JAMA, 2026) followed 130,000 Nurses' Health Study and Health Professionals Follow-Up participants for up to 43 years and found 2-3 cups/day of caffeinated coffee was associated with an 18% lower dementia risk and slower cognitive decline; the effect survived adjustment for the APOE4 risk allele, while decaffeinated coffee showed no equivalent benefit - pointing at caffeine itself as the active factor.
Hazards
- H302 Harmful if swallowedAcute toxicity, oral
Harmonised EU classification (CLP Annex VI, index 613-086-00-5), via PubChem.
Precautionary statements
P264, P270, P301+P317, P330, P501
Identifiers
58-08-2Cn1c(=O)c2c(ncn2C)n(C)c1=ORYYVLZVUVIJVGH-UHFFFAOYSA-NInChI=1S/C8H10N4O2/c1-10-4-9-6-5(10)7(13)12(3)8(14)11(6)2/h4H,1-3H3Weigh it out
Type any one amount. The others follow from the molar mass and density.
Names and synonyms
40 names · show all
- 1H-Purine-2,6-dione, 3,7-dihydro-1,3,7-trimethyl-
- 3,7-Dihydro-1,3,7-trimethyl-1H-purine-2,6-dione
- Guaranine
- Methyltheobromine
- No-doz
- Thein
- Theine
- 1,3,7-Trimethyl-2,6-dioxopurine
- 1,3,7-Trimethylxanthine
- Caffein
- Cafipel
- Alert-pep
- Koffein
- Cafeina
- Mateina
- Refresh'n
- Stim
- Tri-aqua
- 7-Methyltheophylline
- Shape plus
- Caffedrine
- Diurex
- Stay alert
- Synalgos
- Miudol
- Wigraine
- Dasin
- Phensal
- DHCplus
- NSC 5036
- Durvitan
- Cafalgine
- Midron extra
- New cetamol
- Asia migrine
- Palergot-C
- Vivarin
- 1,3,7-Trimethyl-7H-purine-2,6-dione
- 1,3,7-Trimethyl-2,3,6,7-tetrahydro-1H-purine-2,6-dione
- 1,3,7-Trimethyl-3,7-dihydro-purine-2,6-dione
Work with Caffeine
Stereoisomers, salts and isotopologues
The same compound in another form: other stereochemistry, a salt or hydrate, the free acid or base, or an isotope-labelled version.
Similar compounds
Tanimoto similarity of circular fingerprints over the whole catalogue. All similar compounds