reviewed april 2026|next review october 2026|88 physicians psi has verified|12031 published studies
Galanin
Galanin is a 29-amino-acid naturally occurring (the body's own) neuropeptide that modulates pain, feeding, mood, and seizure susceptibility through three receptor subtypes (GalR1, GalR2, GalR3), with levels rising dramatically after seizures and nerve injury as a naturally occurring (the body's own) anticonvulsant signal.
Evidence landscape: 12031 published studies
12,031 published items. 18 human studies and 127 animal studies.
- 18 Human
- 127 Animal
- 55 Reviews
- 11831 Other research
Not FDA-approved as a therapeutic. No galanin receptor-targeted drug has reached FDA approval. Galanin is a naturally occurring (the body's own) neuropeptide, not a pharmaceutical.
Not available as a therapeutic. Galanin does not cross the blood-brain barrier when taken orally or by injection, which is the primary barrier to drug development. Galanin receptor agonists are in early-stage animal study development.
Naturally occurring (the body's own) neuropeptide with over 12,000 published studies. Three receptor subtypes (GalR1, GalR2, GalR3) with opposing effects depending on tissue distribution. The receptor complexity makes selective drug development challenging.
PSI Assessment
A neuropeptide found throughout the central and peripheral nervous system, galanin modulates pain perception, feeding behavior, mood, and seizure susceptibility through three receptor subtypes (GalR1, GalR2, GalR3) that often produce opposing effects depending on their tissue distribution. Galanin levels rise dramatically in the brain following seizures and nerve injury, acting as a naturally occurring (the body's own) anticonvulsant and neuroprotective signal. The therapeutic challenge is that galanin's receptors mediate both beneficial effects (seizure protection, mood regulation) and problematic ones (appetite stimulation, cognitive interference), making selective targeting essential and difficult.
Three receptor subtypes with opposing effects. Levels rise after seizures as a naturally occurring anticonvulsant. Selective targeting is essential and difficult.
The mechanism operates through three receptor subtypes with distinct tissue distributions. GalR1 (inhibitory, widespread) mediates most of galanin's central nervous system effects including pain modulation and appetite stimulation. GalR2 (excitatory/trophic) mediates neurogenesis and neuroprotective effects, often opposing GalR1 actions. GalR3 (mood/anxiety) is concentrated in mood-regulating brain regions. This receptor diversity explains why galanin can simultaneously protect against seizures, stimulate appetite, and modulate mood, and why non-selective galanin-based therapeutics face significant challenges.
What the evidence supports
Galanin modulates pain, feeding, mood, and seizure threshold through three receptor subtypes (GalR1, GalR2, GalR3) with well-characterized and often opposing effects. Galanin levels rise dramatically after seizures and nerve injury, providing a naturally occurring (the body's own) anticonvulsant response. Over 12,000 published studies document the mechanism. GalR2 agonism promotes neurogenesis and neuroprotection in animal models.
What is not yet established
Whether galanin receptor-selective drugs can be developed for clinical use given the opposing effects of GalR1, GalR2, and GalR3. No galanin receptor-targeted drug has reached FDA approval. Whether exogenous galanin administration produces clinically meaningful anticonvulsant or neuroprotective effects. How to achieve receptor subtype selectivity in a therapeutic context.
Research Evidence
The findings below cover the well-characterized receptor system, the anticonvulsant biology, and the barriers to clinical translation.
Evidence by condition
Evidence dimensions across galanin research areas. Seizure/epilepsy and pain modulation have the most extensive animal study data with broad replication. Mood/depression has consistent animal data. Appetite regulation is well-characterized mechanistically. No galanin-based therapeutic has reached clinical development.
| Condition | Mechanism | Animal evidence | Human evidence | Replication |
|---|---|---|---|---|
| Seizure/Epilepsy Research | ||||
| Pain Modulation | ||||
| Mood/Depression | ||||
| Appetite Regulation |
Galanin levels rise dramatically in the brain following seizures and nerve injury, acting as a naturally occurring (the body's own) anticonvulsant and neuroprotective response. GalR1 activation in the hippocampus suppresses seizure activity.
The anticonvulsant mechanism is well-replicated across multiple research groups and animal models. This represents the most therapeutically promising aspect of galanin biology.
GalR2 activation promotes neurogenesis and neuroprotection, often opposing GalR1 effects. This receptor subtype has anxiolytic effects in animal models of anxiety and depression.
The dual receptor system means galanin can produce both beneficial and problematic effects depending on which receptor subtype is preferentially activated. Drug development requires receptor selectivity that has not yet been achieved.
Galanin does not cross the blood-brain barrier when administered systemically, which is the primary barrier to therapeutic development. Gene therapy approaches delivering galanin to seizure foci have shown efficacy in rodent models but remain early-stage.
The blood-brain barrier limitation means that even though galanin's mechanism is well-characterized, delivering it as a drug to the brain remains unsolved. Receptor-selective small molecules or gene therapy are potential paths.
18 Human|127 Animal|55 Reviews
View all 12031 indexed studiesHow Galanin Works
Galanin is a naturally occurring (the body's own) neuropeptide, meaning it is a signaling molecule produced by nerve cells throughout the brain and body. At 29 amino acids long (in humans), galanin works through three different receptor types (GalR1, GalR2, and GalR3), each producing different and sometimes opposite effects depending on where they are located in the nervous system.
Galanin acts like a dimmer switch in the brain. It reduces the excitability of neurons, which is why it can dampen pain signals, prevent seizures, and modulate appetite. When brain activity gets too high (as in a seizure), galanin release increases to calm things down.
For a more detailed view of the biology, here is what researchers have observed at the molecular level.
Galanin is a 29-amino-acid (30 in most mammals) neuropeptide signaling through three G-protein coupled receptors. GalR1 (Gi-coupled, inhibitory, widely distributed) mediates most CNS effects including pain modulation and appetite stimulation. GalR2 (Gq-coupled, excitatory/trophic) mediates neurogenesis, neuroprotection, and often opposes GalR1 actions. GalR3 (Gi-coupled, mood-regulating) is concentrated in anxiety and depression-relevant brain regions. Galanin modulates acetylcholine, serotonin, and norepinephrine release and has potent anticonvulsant effects via hippocampal GalR1 activation.
What is Galanin being studied for?
Researchers are studying Galanin across several health conditions. Each condition below is labeled with the strength of evidence that exists for that specific use, not for Galanin overall. This means a compound can have human studies for one condition but only animal data for another.
Seizure/Epilepsy Research
·Animal StudiesGalanin has potent anticonvulsant effects in animal models of epilepsy. Galanin levels rise after seizures as a naturally occurring protective response. Gene therapy approaches delivering galanin to seizure foci have shown efficacy in rodent models.
Limitations: No human clinical trials. Blood-brain barrier penetration is the primary challenge for systemic delivery. Gene therapy approaches are early-stage.
Pain Modulation
·Animal StudiesGalanin inhibits pain transmission in the spinal cord. Galanin is upregulated in dorsal root ganglia after nerve injury. The role in pain processing is well-established in animal models.
Limitations: The dual receptor system makes drug design complex. Activating the wrong receptor could increase pain rather than reduce it. No pain therapeutics based on galanin have been developed.
Mood/Depression
·Animal StudiesGalanin modulates serotonin and norepinephrine systems that are central to mood regulation. GalR2 activation has anxiolytic effects in animal models.
Limitations: No human mood disorder studies targeting galanin. Whether galanin-targeted drugs could improve on existing antidepressants is theoretical.
Appetite Regulation
·Animal StudiesGalanin stimulates feeding behavior, particularly fat intake. GalR1 activation in the paraventricular nucleus stimulates feeding.
Limitations: No therapeutic applications have been developed for appetite modulation via galanin. The appetite-stimulating effect is a potential side effect of non-selective galanin drugs.
Safety and Regulatory Status
FDA Status: Not applicable as a drug. Galanin is a naturally occurring (the body's own) neuropeptide. No galanin receptor-targeted drug has reached FDA approval or late-stage clinical trials.
Availability: Not available as a therapeutic. Galanin does not cross the blood-brain barrier when administered systemically. GalR2-selective agonists are in early-stage animal study development.
Class context: No safety concerns from normal galanin physiology. The dual receptor system means non-selective galanin drugs could have unpredictable effects, including appetite stimulation (via GalR1) or cognitive interference. Selective receptor targeting is required for therapeutic development.
Galanin is a naturally occurring (the body's own) neuropeptide with no safety concerns from normal physiology. The therapeutic development challenge is receptor selectivity: non-selective galanin drugs could simultaneously produce beneficial effects (seizure protection) and problematic effects (appetite stimulation, cognitive interference). Galanin gene therapy for epilepsy has been studied in animal models but not in humans.
Peptide Structure
Technical molecular data for researchers and clinicians.
Questions and Comparisons
Questions the evidence raises for a Galanin discussion.
Comparison and Related Research
Galanin is most often compared with other neuropeptides involved in CNS modulation.
Related compounds
Frequently Asked Questions
References
Each citation links to the original study on PubMed, the U.S. National Library of Medicine database.
- 1.The discovery paper for galanin, reporting its isolation from porcine intestinal extracts. Named for its N-terminal glycine and C-terminal alanine residues, this 29-amino-acid neuropeptide was subsequently found to be widely distributed throughout the central and peripheral nervous systems, regulating diverse physiological processes from feeding behavior to seizure threshold.Tatemoto K et al., 1983 in FEBS Lett. View on PubMed
- 2.Demonstrated that galanin acts as an endogenous anticonvulsant in the hippocampus. The study showed that galanin signaling through its receptors suppresses seizure activity, establishing a role for this neuropeptide in the brain's natural seizure-control mechanisms and opening research into galanin-based approaches to epilepsy.Mazarati AM et al., 2000 in J Neurosci. View on PubMed
- 3.Review examining the evidence for galanin's role in regulating mood and anxiety. Summarized findings from genetic, pharmacological, and behavioral studies indicating that galanin system activity influences stress resilience, anxiety-like behavior, and depressive states, positioning galanin receptors as potential targets for mood disorder research.Karlsson RM & Holmes A, 2006 in Amino Acids. View on PubMed
- 4.Comprehensive review of the galanin peptide system, covering the three known galanin receptor subtypes (GalR1, GalR2, GalR3), their signaling pathways, and the wide range of biological functions regulated by galanin. Addressed roles in pain modulation, feeding, cognition, seizure control, mood regulation, and neuroendocrine function.Lang R et al., 2007 in Pharmacol Ther. View on PubMed
Medical Disclaimer
This content is for educational and informational purposes only and does not constitute medical advice. The information presented reflects published research as indexed by PSI and should not be used to make treatment decisions. Always consult a qualified healthcare provider before starting, stopping, or modifying any treatment.