SHEET /vs/melatonin-vs-serotonin · COMPARISON
Melatonin vs Serotonin: what is the difference?
How they differ
Melatonin is made from serotonin in two enzymatic steps, so one is the raw material for the other rather than an alternative to it. The pineal gland runs that conversion in darkness, which is why melatonin is the body's nightfall signal and why light at night suppresses it. Serotonin's role is broader and mostly daytime and mostly not in the brain at all: around ninety percent of the body's serotonin is in the gut. The structures show the two added groups, an acetyl on the nitrogen and a methyl on the oxygen, which take serotonin's 176.21 to melatonin's 232.28. Melatonin is sold over the counter in the US and is prescription-only in much of Europe, while serotonin is not sold as a supplement at all because it does not cross into the brain from the bloodstream.
Side by side
| Melatonin | Serotonin | |
|---|---|---|
| Formula | C13H16N2O2 | C10H12N2O |
| Molecular weight | 232.28 g/mol | 176.21 g/mol |
| Family | Amines | Neurotransmitters |
| Everyday group | Body | Body |
| Functional groups | Aromatics, Amides, Ethers | Amines, Aromatics, Phenols |
| GHS signal wordThe supplier-filed hazard label, not a statement about ordinary use. | not recorded | Danger |
| Oral LD50A single acute animal measure. It ranks nothing about human safety. | 3,200 mg/kg (oral, rat) | not recorded |
| Half-life | 0.75 h | not recorded |
| CAS number | 73-31-4 | 50-67-9 |
| PubChem CID | 896 | 5202 |
Structural similarity 0.39 of 1, computed as a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.
Common questions
- What is the difference between Melatonin and Serotonin?
- Melatonin is made from serotonin in two enzymatic steps, so one is the raw material for the other rather than an alternative to it. The pineal gland runs that conversion in darkness, which is why melatonin is the body's nightfall signal and why light at night suppresses it. Serotonin's role is broader and mostly daytime and mostly not in the brain at all: around ninety percent of the body's serotonin is in the gut.
- Is Melatonin bigger than Serotonin?
- Melatonin is the heavier molecule, 232.28 g/mol against 176.21 g/mol for Serotonin. Melatonin is C13H16N2O2 and Serotonin is C10H12N2O.