Neuropeptide research covers the short signaling peptides that neurons release alongside classical neurotransmitters — molecules such as neuropeptide Y, substance P, orexin and galanin that modulate feeding, pain, arousal, stress and social behavior. Our neuropeptide topic page collects the catalog items laboratories order for this work: synthetic peptide standards, species-specific fragments, polyclonal antisera, labeled tracers and immunoassay kits, organized by peptide family. This guide explains which families sit inside that topic, what each is studied for, and which reagent format fits which experiment.
What counts as a neuropeptide in this catalog
We group items under the neuropeptide topic when the parent molecule is expressed in neural or neuroendocrine tissue and acts on G-protein-coupled receptors in the nervous system. That includes hypothalamic feeding peptides, opioid peptides, tachykinins, and stress-axis peptides. Many families overlap with other topics — NPY appears in obesity research, CGRP in cardiovascular work — so the same family page may be reachable from more than one topic. Every item is supplied strictly for in-vitro and animal research; nothing in this section is a drug product.
The core neuropeptide families researchers order
These are the most requested family pages in the neuropeptide topic, with the research areas each is typically ordered for:
- Neuropeptide Y (NPY) — one of the most abundant peptides in mammalian brain; studied in feeding circuits, anxiety models and sympathetic signaling. Fragments and receptor-selective analogs distinguish Y1/Y2/Y5 pharmacology.
- Substance P — the prototype tachykinin, central to pain-transmission and neurogenic-inflammation studies; also ordered as fragments for NK1 receptor mapping.
- Orexin (hypocretin) — orexin-A and orexin-B standards support sleep/wake and arousal research, including narcolepsy models.
- Galanin — studied in seizure, mood and feeding models; species variants (rat, human, porcine) differ in sequence, so matching the standard to the model organism matters.
- Neurotensin — dopamine-circuit and gut–brain research; NT(8–13) is the common active fragment.
- Somatostatin — cortical interneuron markers and receptor-subtype pharmacology; both SST-14 and SST-28 are stocked.
- CGRP — calcitonin gene-related peptide, the best-known migraine-research target; alpha and beta isoforms plus the antagonist fragment CGRP(8–37).
- Oxytocin and vasopressin — social-behavior, stress and osmoregulation research; antibodies and EIA kits are frequent companions to the peptides themselves.
- Dynorphin, enkephalin and endorphin — the three classical opioid-peptide families, used in receptor-selectivity and stress-analgesia studies.
- PACAP — a pleiotropic neuropeptide studied in neuroprotection and circadian biology; PACAP-27 and PACAP-38 forms behave differently in assays.
- Kisspeptin — the upstream regulator of GnRH neurons, central to reproductive-neuroendocrinology work.
- Neuropeptide S and neuropeptide W — newer arousal- and feeding-related families with growing literatures.
Which product formats the topic contains
Each family page lists whatever formats exist for that family. Across the neuropeptide topic you will find four product types:
- Research peptides — lyophilized synthetic standards, usually 98%+ HPLC purity, in microgram-to-milligram fills. These are the workhorses for receptor assays, standard curves and electrophysiology perfusion.
- Labeled peptides — biotinylated, fluorescent (FAM/TAMRA) and radioiodinated versions for binding assays, imaging and receptor autoradiography. Neuropeptide binding studies historically lean on I-125 tracers.
- Polyclonal antibodies and antisera — raised against the parent peptide for immunohistochemistry on brain sections and for RIA/EIA detection.
- ELISA, EIA and RIA kits — quantify endogenous peptide in plasma, CSF or tissue extracts; check the standard range against your expected concentrations before ordering.
How laboratories choose within a family
Four decisions come up repeatedly. First, species sequence: rat NPY and human NPY differ by a single residue, but for families like galanin the differences are larger and cross-reactivity of antibodies is not guaranteed — family pages state the species of each item. Second, full-length versus fragment: fragments such as NPY(13–36) or CGRP(8–37) are receptor-subtype tools, not substitutes for the parent peptide in quantitation. Third, label or no label: unlabeled peptide plus a labeled tracer is the classic competition-binding pair. Fourth, peptide versus kit: if the question is "how much endogenous peptide is in my sample," an immunoassay kit is usually faster than assembling antibody, tracer and standards separately.
Handling notes specific to neuropeptides
Most neuropeptides are small (1–4 kDa), lyophilized, and stable for years at −20 °C when dry. Reconstituted solutions are a different matter: peptides with methionine (some tachykinins) oxidize, and cysteine-containing families can dimerize. Standard practice is to reconstitute in a small volume, aliquot once, and avoid repeated freeze–thaw — the same workflow described in our peptide storage guide and aliquoting guide. For quantitative work, confirm content against the certificate of analysis rather than assuming label mass equals peptide mass; our COA guide explains peptide content versus gross weight.
Where to go next
Browse the full neuropeptide topic, or start from the research catalog hub if your target spans topics. Adjacent guides in this series cover the obesity and appetite section, which shares many hypothalamic families with this topic, and the neurodegeneration section for amyloid, tau and neurotrophin reagents.