Galanin
Galanin is a 29-30 aa neuropeptide activating GALR1/2/3 receptors to modulate pain, memory, mood, appetite, and autonomic function. Implicated in Alzheimer's disease (expands into hippocampus as cholinergic neurons degenerate).
Community Rating
No ratings yet
Compound Profile
Galanin
Key Data
Research reference only
Research Focus
Preclinical data
⚠ Research & Educational Use Only. Galanin is a research chemical documented here for scientific education. All information references peer-reviewed literature and preclinical/clinical study data. Not for human consumption. Not medical advice. Consult a licensed researcher or healthcare professional before any laboratory use.
- Analgesic: spinal galanin release (from primary afferents and descending pathways) suppresses pain transmission via GALR1
- Neuroprotective: galanin receptor activation (GALR2) promotes neuronal survival and neurite outgrowth
- Regulates mood — GALR1 hypofunction linked to depression (galanin is co-expressed in serotonergic raphe neurons)
- Galanin is not FDA-approved for human use. It is a research chemical for scientific study only.
Research At a Glance
- Analgesic: spinal galanin release (from primary afferents and descending pathways) suppresses pain transmission via GALR1
- Neuroprotective: galanin receptor activation (GALR2) promotes neuronal survival and neurite outgrowth
- Regulates mood — GALR1 hypofunction linked to depression (galanin is co-expressed in serotonergic raphe neurons)
- Modulates memory consolidation — hippocampal galanin inhibits acetylcholine release via GALR1 (memory-impairing in excess)
In Plain English
Simple summaryGalanin is a 29-30 amino acid neuropeptide (29 in humans, 30 in other mammals) found throughout the brain, spinal cord, and peripheral nervous system. It's a broad modulator -- galanin doesn't have one primary role, it modulates many. It inhibits acetylcholine release (and is elevated in the cholinergic basal forebrain nuclei of Alzheimer's patients, suggesting a compensatory role), suppresses pain transmission in the spinal cord, stimulates appetite and fat intake, regulates sleep, modulates mood and anxiety, and influences insulin secretion from the pancreas. Three galanin receptor subtypes (GalR1, GalR2, GalR3) mediate these diverse effects with different regional distributions.
- Analgesic: spinal galanin release suppresses pain transmission via GALR1
- Neuroprotective: galanin receptor activation (GALR2) promotes neuronal survival and neurite outgrowth
- Regulates mood — GALR1 hypofunction linked to depression
The full scientific detail, mechanisms, citations, and dosing data, follows below.
What is Galanin?
Tap any underlined term for an instant definition.
Galanin is a 29-amino acid neuropeptide in most mammals (30 amino acids in humans due to a C-terminal extension) that is widely distributed in both the central nervous system and peripheral tissues. It was first isolated from porcine intestine in 1983 by Tatemoto et al.
Galanin is produced in the hypothalamus, brainstem (particularly locus coeruleus and raphe nuclei where it co-localizes with norepinephrine and serotonin), spinal cord dorsal horn, enteric nervous system, adrenal medulla, and peripheral sensory neurons. It acts via three G-protein-coupled receptors (all Gi-coupled, inhibitory)
- **GALR1**: Wide distribution; coupled to Gi → inhibits cAMP; primary mediator of galanin's memory-suppressing effects in hippocampus
- **GALR2**: Coupled to Gq (stimulatory PLC) and Gi; neuroprotective, promotes neurite outgrowth
- **GALR3**: Limited brain distribution; modulates sleep and stress responses
**Alzheimer's Disease connection:** The most clinically relevant aspect of galanin is its role in Alzheimer's disease (AD). In the basal forebrain, galanin-positive fibers from the hypothalamus hyper-innervate cholinergic neurons as they degenerate in AD — galanin fiber density increases 2-5 fold in correlation with cholinergic neuron loss. This hyperinnervation is believed to further suppress acetylcholine release via GALR1, worsening the cholinergic deficit that contributes to memory impairment in AD. GALR1 antagonism has been proposed as a strategy to improve cholinergic function in early AD.
**Pain research:** Galanin expression in dorsal root ganglion neurons is dramatically upregulated after nerve injury (5-10 fold). This injury-induced galanin plays a complex role: GALR1 activation is inhibitory (analgesic), while GALR2 may facilitate certain aspects of neuropathic pain. Spinal galanin from primary afferents modulates nociception, and intrathecal galanin produces analgesia in multiple pain models.
**Serotonin/depression connection:** Galanin co-localizes with serotonin in dorsal raphe neurons. GALR1 activation inhibits serotonergic firing. Chronic stress elevates galanin expression in the raphe, potentially dampening serotonin transmission — a mechanism proposed to link chronic stress to depression. GALR2 agonism may have antidepressant effects (stimulates BDNF, promotes neurogenesis).
By the Numbers
Key Research Benefits
Documented effects observed in preclinical and clinical studies on Galanin. See all Cognitive Enhancement peptides for comparison.
Side Effects & Risks
Adverse effects reported in the research literature. All data sourced from preclinical and clinical study reports. View all peptides' side effects →
Dosing Data from the Literature
Doses referenced below are sourced from published preclinical and clinical studies. Use the peptide dose calculator to convert these values to injection volume.
Galanin research protocols (basic neuroscience applications):
ICV injection (rodent studies): 0.3-3 nmol for memory, appetite, and pain studies Intrathecal: 1-10 nmol for spinal analgesia studies Peripheral (intraperitoneal): 10-100 nmol/kg for autonomic and metabolic studies
Drug development approach: GALR2-selective peptide agonists (AR-M1896, M617) and small molecule GALR1/2 modulators are in preclinical development for depression and pain
Administration in Research Settings
Standard reconstitution and administration methodology for laboratory research use.
Primarily used as a research tool via ICV, intrathecal, or direct intracerebral injection for CNS studies. Peripheral IV use for autonomic, cardiovascular, and metabolic research.
What the research doesn't show
Despite being studied for decades, no galanin-targeting drugs have reached approval. The receptor subtype complexity means it's been difficult to develop selective agonists or antagonists that produce clean, predictable clinical effects. Galanin is more valuable as a research tool for understanding brain circuit modulation than as a therapeutic target, at least with current drug design capabilities.
Medical Expert Videos
Physicians, researchers, and pharmacologists explain Galanin, covering mechanisms of action, clinical context, and study findings.
Videos sourced from YouTube search. KnowYourPeptide does not endorse any individual creator. For research education only.
The Bottom Line
Galanin has a growing body of preclinical evidence and a well-characterised safety profile in research settings. The most-studied application is: analgesic: spinal galanin release suppresses pain transmission via galr1.
The most commonly reported side effect in research subjects is memory impairment with excessive galanin activity — particularly relevant in alzheimer's disease context. It is a research chemical, not approved for human use.
Frequently Asked Questions
Explore Further
Quick Reference
How It Compares
Neuropeptide Y is another potent appetite-stimulating neuropeptide but has different receptor pharmacology and stronger carbohydrate-appetite effects (vs galanin's fat preference). Substance P and CGRP also modulate spinal pain, but galanin's pain effects are primarily inhibitory at the spinal level. In the Alzheimer's context, galanin is unusual among neuropeptides for being elevated rather than depleted -- suggesting it may be both a marker and a player in cholinergic neurodegeneration.
Compare Galanin side-by-sideResearch Use Only
This information is for educational research purposes only. This is not medical advice. Consult a qualified healthcare professional.