SHEET /vs/dopamine-vs-norepinephrine · COMPARISON
Dopamine vs Norepinephrine: what is the difference?
How they differ
Norepinephrine is made from dopamine by a single enzyme adding one hydroxyl group, so this pair is a molecule and its immediate product, C8H11NO2 against C8H11NO3. The body runs the chain tyrosine to L-dopa to dopamine to norepinephrine to adrenaline, and each step is one small modification. Functionally they diverge: dopamine dominates in reward, motivation and movement circuits, and norepinephrine drives arousal, attention and the fight-or-flight response, and acts as a hormone as well as a neurotransmitter. Several medicines act on both at once, which is why stimulant drug descriptions usually name the pair together. The reported oral LD50 for norepinephrine is 20 mg/kg in mice, which makes it one of the more acutely toxic entries in this catalog.
Side by side
| Dopamine | Norepinephrine | |
|---|---|---|
| Formula | C8H11NO2 | C8H11NO3 |
| Molecular weight | 153.18 g/mol | 169.18 g/mol |
| Family | Neurotransmitters | Neurotransmitters |
| Everyday group | Body | Body |
| Functional groups | Amines, Aromatics, Phenols | Alcohols, Amines, Aromatics, Phenols |
| GHS signal wordThe supplier-filed hazard label, not a statement about ordinary use. | Warning | Danger |
| LD50A single acute animal measure. It ranks nothing about human safety. | 59 mg/kg (iv, mouse) | 20 mg/kg (oral, mouse) |
| CAS number | 51-61-6 | 51-41-2 |
| PubChem CID | 681 | 439260 |
Structural similarity 0.42 of 1, computed as a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.
Common questions
- What is the difference between Dopamine and Norepinephrine?
- Norepinephrine is made from dopamine by a single enzyme adding one hydroxyl group, so this pair is a molecule and its immediate product, C8H11NO2 against C8H11NO3. The body runs the chain tyrosine to L-dopa to dopamine to norepinephrine to adrenaline, and each step is one small modification. Functionally they diverge: dopamine dominates in reward, motivation and movement circuits, and norepinephrine drives arousal, attention and the fight-or-flight response, and acts as a hormone as well as a neurotransmitter.
- Is Dopamine bigger than Norepinephrine?
- Norepinephrine is the heavier molecule, 169.18 g/mol against 153.18 g/mol for Dopamine. Dopamine is C8H11NO2 and Norepinephrine is C8H11NO3.
Read the full records: Dopamine and Norepinephrine.