Nicotine vs Caffeine: what is the difference?
Nicotine switches on acetylcholine receptors directly while caffeine blocks adenosine receptors, and nicotine is far more habit forming and clears faster.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Each molecule's own drawing, as its page shows it. The common core, 2 of 14 atoms, is too small to align on.
Side by side
| Nicotine | Caffeine | |
|---|---|---|
| Molecular weightCalculated PubChem | 162.23 g/molC10H14N2 | 194.19 g/molC8H10N4O2 |
| Hydrogen-bond donorsCalculated PubChem | 0 | 0 |
| Half-life in the bodyEditorial MoleculeFinder curated | about 2 h | about 5 h |
| Where each turns upEditorial MoleculeFinder food and product lists | Not on our lists |
|
| FamilyEditorial MoleculeFinder curated | Plant alkaloids, Stimulants | Plant alkaloids, Stimulants |
| Everyday groupEditorial MoleculeFinder curated | Plant | Food & flavor |
| Hazard labelReported ECHA, EU CLP Regulation, Safe Work Australia via PubChem | Danger | Warning |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | 188 mg/kgpure nicotine, rat, oral | 192 mg/kgpure caffeine, 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.
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Hazard labelfrom sourceECHA, EU CLP Regulation, Safe Work Australia via PubChem
- Oral LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- EU CLP Regulationfrom sourceAttributionSource: EUR-Lex, Regulation (EC) No 1272/2008, © European Union.
- Safe Work Australiafrom sourceAttributionSource: Safe Work Australia, Hazardous Chemical Information System, © Commonwealth of Australia, CC BY 4.0.
- Identifiersfrom sourcePubChemPubChem CID 89594 (Nicotine) and 2519 (Caffeine).
In more detail
Both are plant alkaloids that plants make to poison insects, and both are stimulants in people, but they act on completely different receptors. Nicotine binds acetylcholine receptors directly; caffeine works by blocking adenosine, the molecule that builds up while you are awake and makes you feel sleepy. The habit-forming pull is not comparable: nicotine reaches the brain within seconds of a puff and is strongly reinforcing, and caffeine produces a mild dependence that shows up mostly as a headache when it stops. Nicotine also clears far faster, a half-life near 2 hours against caffeine's 5, which is part of why smoking is paced in minutes and coffee in hours. Their oral LD50 values in rats are almost identical at 188 and 192 mg/kg, which says nothing useful about how each is actually encountered.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Nicotine and Caffeine?
- Nicotine switches on acetylcholine receptors directly while caffeine blocks adenosine receptors, and nicotine is far more habit forming and clears faster.
- Is Nicotine bigger than Caffeine?
- Caffeine is the heavier molecule, 194.19 g/mol against 162.23 g/mol for Nicotine. Nicotine is C10H14N2 and Caffeine is C8H10N4O2.
- Which has the lower reported LD50, Nicotine or Caffeine?
- Nicotine, at 188 mg/kg (oral, rat), against 192 mg/kg (oral, rat) for Caffeine. 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.