Overview
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In plain language
Neuropeptide Y (NPY) is a natural messenger molecule in the brain and nerves. It is a chain of 36 amino acids and one of the most common peptides in the brain.
It is a powerful appetite signal: it makes animals eat more and store energy. It also helps shape how we respond to stress and narrows blood vessels. NPY is studied to understand obesity, stress and anxiety, but it is not a drug.
For students
NPY was isolated in 1982 by Tatemoto and colleagues from pig brain and named for the tyrosine (Y in the one-letter code) residues at both ends; the C-terminal tyrosine is amidated. It belongs to the pancreatic polypeptide family, with PYY and PP, and folds into a hairpin "PP-fold."
In the hypothalamic arcuate nucleus, NPY/AgRP neurons drive feeding and reduce energy expenditure; leptin inhibits them. NPY acts through Y1, Y2, Y4 and Y5 receptors and is co-released with norepinephrine from sympathetic nerves, where it causes vasoconstriction.
For researchers and instructors
Stress research. Higher NPY levels have been associated with stress resilience in soldiers and in animal models; intranasal NPY has been explored in small PTSD studies.
Drug development. Y5 receptor antagonists were tested for obesity but produced only small effects, illustrating redundancy in appetite circuits.
Status. Natural neuropeptide; not a drug. Graded Preclinical as a therapeutic.
Molecular identity
- Amino acids
- 36
- Molecular weight
- ~4,271.7 Da
- Formula
- C₁₈₉H₂₈₅N₅₅O₅₇S
- Sequence
- YPSKPDNPGEDAPAEDMARYYSALRHYINLITRQRY-NH₂
Sequence map
Hydropathy
Kyte–Doolittle score per residue. Positive values are water-repelling.
Origin and history
Neuropeptide Y was isolated in 1982 by Kazuhiko Tatemoto and Viktor Mutt at the Karolinska Institute in Stockholm. They had a clever method: search tissue extracts for peptides ending in a chemical amide group, a sign of hormones.
It is named for the tyrosine (code letter Y) at both of its ends. It turned out to be one of the most abundant peptides in the brain and a powerful driver of appetite.
Key people
- Kazuhiko Tatemoto & Viktor MuttKarolinska Institute
Timeline
- 1980
Related peptide YY discovered
- 1982
Neuropeptide Y isolated
- 1980s–90s
Role in appetite established
See every peptide on one history timeline.
Human evidence
Studied mainly in animals and through observational human research; it is not a treatment.
Registration and enrollment are not proof of benefit; check study results directly.
Explore original publications and distinguish preclinical findings from controlled human evidence.
Safety and regulatory status
See every compound on the regulatory tracker.
Natural neuropeptide; not a drug.
This profile is educational and does not provide treatment, dosing or sourcing guidance.
Sources
- PubMed literature search: Neuropeptide Y
- PubChem compound search: Neuropeptide Y
- Tatemoto et al. 1982, Nature
- ClinicalTrials.gov search: Neuropeptide Y
Hernandez Gener, E. (2026, November 7). Neuropeptide Y: molecular data, research history and evidence. VALREXA Biosciences. https://valrexa.com/peptides/neuropeptide-y.html
APA style · Last reviewed November 7, 2026 · Our editorial standardsLast reviewed November 7, 2026. Trial and regulatory status can change; confirm in the linked registries. This profile is educational and is not medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error · Corrections policy