Quick summary
Galanin is a 29-amino acid neuropeptide broadly involved in pain processing, cognition, mood, and feeding. Its overexpression in Alzheimer's disease brains (up to 200% increases) drives sustained research into GalR1/GalR3 antagonists and GalR2 agonists as potential AD and mood disorder therapeutics.
Overview
Galanin is a 29-amino acid neuropeptide (30 AA in humans) widely distributed in the central and peripheral nervous system and GI tract. It is one of the most multifunctional neuropeptides known, modulating pain processing, cognition, mood, feeding, pancreatic insulin release, and cardiovascular function. Galanin overexpression has been documented in Alzheimer's disease brains, generating sustained research interest in galanin receptor subtypes as therapeutic targets.
Mechanism of action
Galanin acts through three G protein-coupled receptors: GalR1, GalR2, and GalR3. GalR1 and GalR3 couple to Gi/o, reducing cAMP and inhibiting neuronal firing. GalR2 couples to Gq/11, activating phospholipase C and increasing intracellular calcium. In the spinal cord dorsal horn, galanin co-released with substance P inhibits nociceptive transmission via GalR1. In Alzheimer's disease, galanin hyperinnervation of surviving cholinergic neurons in the basal forebrain is proposed to inhibit acetylcholine release, potentially contributing to cognitive decline. GalR2 may alternatively exert neuroprotective effects.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| nociception / neuroscience research (animal) | intravenous | 1–100 nmol | per experimental protocol (often intrathecal in spinal pain models) |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Alzheimer's disease research drives much of the current galanin field. Postmortem brains of AD patients show up to 200% increases in galanin expression and receptor density in basal forebrain regions. Selective GalR1/GalR3 antagonists and GalR2 agonists are under preclinical investigation for AD and mood disorders. Galanin also modulates insulin secretion from pancreatic islets, making it relevant to diabetes research. Pain models show a dual role: pro-nociceptive at supraspinal sites and anti-nociceptive spinally. No galanin-targeting drug has reached clinical approval.[1][2][3]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Galanin for synergistic effects.
Legal status
Galanin peptide is available for laboratory research only with no approved clinical applications.
Sourcing & access
Research compound
Galanin is classified as a research compound. Regulatory status varies by jurisdiction. Always verify current legal status and source from vendors providing third-party certificates of analysis (COA).
Frequently asked questions
Galanin is a 29-amino acid neuropeptide (30 AA in humans) widely distributed in the CNS, PNS, and GI tract. It is one of the most multifunctional neuropeptides known, modulating pain processing, cognition, mood, feeding, insulin release, and cardiovascular function.
Galanin acts through three GPCRs: GalR1 and GalR3 couple to Gi/o (reducing cAMP and inhibiting neuronal firing), while GalR2 couples to Gq/11 (activating phospholipase C). In the spinal cord, galanin inhibits pain transmission via GalR1. In Alzheimer's disease, galanin hyperinnervation may inhibit acetylcholine release from surviving cholinergic neurons.
Galanin is a research-only compound. In animal studies, high doses can cause sedation, increased food intake, and hypotension. No galanin-targeting drug has reached clinical approval, and the peptide itself is not approved for human administration.
Postmortem brains of Alzheimer's patients show up to 200% increases in galanin expression in basal forebrain regions. Galanin hyperinnervation of surviving cholinergic neurons may contribute to cognitive decline by inhibiting acetylcholine release. Selective GalR1/GalR3 antagonists and GalR2 agonists are under preclinical investigation for AD.