Galanin-like Peptide (GALP)
An endogenous hypothalamic peptide that links body-fat signals to appetite and the reproductive axis. A research peptide, not a drug
Galanin-like peptide (GALP) is an endogenous 60-amino-acid neuropeptide made by a small, discrete group of neurons in the arcuate nucleus of the hypothalamus — the brain’s appetite-and-energy hub — and in the posterior pituitary. It was discovered in 1999 because it activates the galanin receptor GalR2, and it shares a short stretch of its sequence with galanin, though its biology is its own. What makes GALP interesting is that its neurons carry receptors for leptin, the fat-derived hormone, so GALP sits at the crossroads where the body’s metabolic state is translated into behaviour: it influences feeding and energy balance, stimulates the release of luteinizing hormone to drive the reproductive axis, and suppresses the thyroid axis. Because of this it is studied as a link between metabolism and reproduction and as a possible lead against obesity. GALP is a research peptide; it is not an approved medicine and has not been given to people as a treatment.
No established human dose Details ↓
Recommended Dosing
No established human dose
Galanin-like peptide is an endogenous human peptide that has never been given to people as a treatment. The human evidence is its gene and anatomy; the functional studies are in animals and cells, where GALP is injected into the brain or applied to tissue at experimental amounts that do not carry over to people.
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What is it?
Galanin-like peptide was isolated from the pig hypothalamus in 1999, picked out because it switched on the galanin receptor GalR2. It is a 60-amino-acid peptide with a non-amidated tail, and it shares a short run of about 13 amino acids with the neuropeptide galanin — which is where its name comes from — but the rest of the molecule, and much of its biology, is distinct. In the adult brain GALP is made by a surprisingly small and discrete population of neurons, concentrated almost entirely in the arcuate nucleus of the hypothalamus and in the posterior pituitary.
That location is telling. The arcuate nucleus is the brain’s main sensor of the body’s energy state, and GALP neurons carry receptors for leptin, the hormone released by fat tissue. When leptin rises, GALP gene expression rises; when animals fast, or in leptin-receptor-deficient obese rats and in diabetic rats, GALP expression falls sharply. GALP is therefore regulated as a downstream relay of metabolic signals, positioned to pass that information on to the circuits that control appetite and hormones.
GALP’s effect on feeding is two-sided. Injected into the brain it acutely stimulates food intake — in one study about ten times more potently than galanin — and can produce anxiety-like behaviour, yet over a longer window it reduces food intake and body weight and raises energy expenditure, a net anti-obesity action. It works in part by changing the release of other appetite peptides, stimulating neuropeptide Y and reducing cocaine-and-amphetamine-regulated transcript (CART) from hypothalamic tissue, and it suppresses the thyroid axis by lowering thyroid-stimulating hormone.
Its other headline role is in reproduction. GALP fibres make close contact with the LHRH (GnRH) neurons that govern the reproductive axis, and central GALP raises plasma luteinizing hormone — an effect that depends on LHRH neurons and is abolished by blocking the LHRH receptor, while GALP does not act directly on the pituitary. Linking leptin on one side to LH on the other, GALP is studied as a messenger coupling nutritional status to fertility.
Galanin-like peptide is an endogenous human peptide and a research tool, not a medicine. No published study has given GALP to people as a treatment — the human side is its gene and anatomy, and the functional work is in animals and cells — it is approved nowhere, and material sold online as ‘galanin-like peptide’ or ‘GALP’ is an unregulated research chemical. Nothing here is a dose or a therapy; this page records what the published science says about the peptide.
Mechanism of Action
Galanin-like peptide is a hypothalamic neuropeptide from leptin-sensitive arcuate-nucleus neurons that activates the galanin receptors. It links the body’s metabolic state to feeding and energy balance and to the reproductive axis, and it suppresses the thyroid axis.
Leptin-sensing relay
GALP neurons in the arcuate nucleus carry leptin receptors; GALP gene expression rises with leptin and falls with fasting, diabetes and leptin-receptor deficiency (PMID 10875277) — a downstream relay of metabolic state.
Feeding, energy and thyroid axis
Acting through the galanin receptors, GALP acutely stimulates food intake (about 10x galanin) but longer-term reduces feeding and body weight (PMIDs 11958845, 15620409); it shifts NPY and CART release and lowers thyroid-stimulating hormone (PMID 12624534).
Reproductive axis (LH)
GALP fibres contact LHRH (GnRH) neurons; central GALP raises plasma luteinizing hormone through an LHRH-dependent hypothalamic mechanism, not by acting on the pituitary directly (PMID 11459819) — coupling nutritional state to reproduction.
Published Research
These are studies of galanin-like peptide read from their PubMed abstracts on November 6, 2026. They include two reviews of GALP as a hypothalamic link between energy homeostasis and reproduction, an animal study of its stimulation of food intake, an animal study of its stimulation of luteinizing hormone, a study of its regulation by leptin, and a study of its effects on feeding and the thyroid axis. Galanin-like peptide has not been given to people as a treatment in any published study; the human evidence is its gene and anatomy.
GALP: a hypothalamic regulator of energy and reproduction
A review of galanin-like peptide, a 60-amino-acid neuropeptide from arcuate-nucleus and posterior-pituitary neurons that binds and activates the galanin receptors GalR1-3. GALP gene expression is regulated by metabolic signals — leptin, insulin, thyroid hormone, glucose — and GALP neurons connect to other feeding and reproductive circuits. The review concludes GALP has a role in energy homeostasis and reproduction, possibly via a still-unidentified GALP-specific receptor.
GALP in feeding, energy metabolism and reproduction
A review of galanin-like peptide in the brain. Produced in the arcuate nucleus, GALP forms networks with several feeding-related peptide neurons and is involved in the control of food intake and energy balance — so may matter for obesity — and it regulates plasma luteinizing hormone by activating GnRH neurons, placing it in the reproductive system as well. The review summarises GALP’s roles across these physiological systems.
GALP stimulates food intake in the rat
Galanin-like peptide, isolated as a GalR2 ligand, was given into the brain of rats and induced food intake with about ten times the orexigenic potency of galanin, along with anxiety-like behaviour at 1 nmol. The study identified GALP as a novel orexigenic and anxiogenic peptide (an acute, preclinical result; longer-term GALP instead reduces feeding).
GALP stimulates LH via LHRH neurons
Given into the brain of male rats, galanin-like peptide raised plasma luteinizing hormone without changing other pituitary hormones, and activated LHRH (GnRH) neurons (shown by c-Fos). The LH response was abolished by an LHRH-receptor antagonist, and GALP did not release LH directly from pituitary cells — showing GALP drives gonadotropin secretion through a hypothalamic, LHRH-dependent mechanism (a preclinical result).
GALP is regulated by leptin
Mapping GALP messenger RNA in the rat brain, this study found GALP-expressing cells in the arcuate nucleus, dorsomedial nucleus, median eminence and pituitary, overlapping the distribution of leptin receptors. Fasting reduced the number of GALP-expressing cells, while treating fasted rats with leptin produced a four-fold increase — identifying GALP as a target of leptin regulation in the hypothalamus (a tissue gene-expression result).
GALP on feeding and the thyroid axis
Injected into the rat paraventricular nucleus, galanin-like peptide increased food intake (more potently than galanin) and, like galanin, lowered circulating thyroid-stimulating hormone. In hypothalamic explants, GALP stimulated release of the orexigenic peptide neuropeptide Y and reduced the anorectic peptide CART, and both GALP and galanin inhibited thyrotrophin-releasing hormone — detailing how GALP acts on energy balance and the thyroid axis (a preclinical and explant result).
No Established Human Dose
Galanin-like peptide is an endogenous human peptide that has never been given to people as a treatment. The human evidence is its gene and anatomy; the functional studies are in animals and cells, where GALP is injected into the brain or applied to tissue at experimental amounts that do not carry over to people. No regulator has approved any dose, and no published human dose exists, so no amount is printed here.
What this rests on: PMID 20558195, PMID 11958845, PMID 11459819.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes Galanin-like Peptide (GALP) is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
Unknown: no human dose of Galanin-like Peptide (GALP) has been established (see No Established Human Dose below), so there is no amount to work out. The reconstitution calculator does the arithmetic for any vial, water and dose.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store Galanin-like Peptide (GALP), before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long Galanin-like Peptide (GALP) stays intact once mixed.
How it is taken
Unknown: with no established human dose, there is no established way of taking Galanin-like Peptide (GALP). What the human studies gave and how is set out under No Established Human Dose.
What to expect, and when
How long it stays in the body: a half-life of not established for humans as a drug; an endogenous signalling peptide. After about five half-lives almost none is left.
When effects appear: unknown; no source on this page gives a time to effect for Galanin-like Peptide (GALP). Results reported in the studies are under Published Research.
Source: half-life: PMID 20558195.
Side effects, and when to stop or get help
From the Side Effects section: No human adverse-event data exist: no published study has administered galanin-like peptide to people; In animals, acute central GALP stimulates feeding and produced anxiety-like behaviour (PMID 11958845) — effects of a signalling peptide, not a safety profile; GALP affects the reproductive (LH) and thyroid axes (PMIDs 11459819, 12624534), so endocrine effects would be expected if it were administered; Material sold online as ‘galanin-like peptide’ or ‘GALP’ is an unregulated research chemical of unverified content. Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Galanin-like Peptide (GALP). Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“Galanin-like peptide is an endogenous peptide that has not been given to people as a drug, so there is no human safety profile; the points below reflect that research status”).
Interactions
Unknown: a PubMed search for human interaction studies of Galanin-like Peptide (GALP) (reviewed 2026-11-06) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Galanin-like Peptide (GALP) products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Research Chemical (Not a drug: Drugs@FDA and the openFDA label endpoint hold no record, and FDA GSRS and ChEMBL hold no substance record for galanin-like peptide (searched November 6, 2026)). Sport: Not on the 2026 List.
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
Galanin-like peptide is an endogenous peptide that has not been given to people as a drug, so there is no human safety profile; the points below reflect that research status.
Contraindications & Cautions
Galanin-like peptide has no approved use and no label. These points reflect its endogenous, research status.
Legal Status
Galanin-like peptide is an endogenous human peptide studied as a research compound; it is not a drug and is not approved in any country.
Frequently Asked Questions
?What is galanin-like peptide?
An endogenous human neuropeptide of 60 amino acids, made in the hypothalamic arcuate nucleus and posterior pituitary. It shares a short stretch with galanin and activates the galanin receptors (GalR1-3, preferring GalR2), but its biology is its own.
?What does it do?
Its neurons sense leptin (PMID 10875277), and GALP links the body’s energy state to behaviour: it affects feeding and energy balance (PMIDs 11958845, 15620409), stimulates luteinizing hormone to drive the reproductive axis (PMID 11459819), and suppresses the thyroid axis (PMID 12624534).
?Is it a treatment for anything?
No. Galanin-like peptide is a research peptide used to study the link between metabolism and reproduction, and as an anti-obesity lead; no human trial has administered it, and it is approved nowhere.
?Is it approved or available to buy?
No. Galanin-like peptide is not a medicine, has no FDA application or label, and is approved nowhere. Material sold online as galanin-like peptide or GALP is an unregulated research chemical. Grey Peptides lists no sellers and recommends no source; this page records the published science.
References
- [review] Lawrence C, et al. "Galanin-like peptide (GALP) is a hypothalamic regulator of energy homeostasis and reproduction." Front Neuroendocrinol, 2011;32(1):1-9. PMID: 20558195.
- [review] Kageyama H, et al. "Galanin-like peptide in the brain: effects on feeding, energy metabolism and reproduction." Regul Pept, 2005;126(1-2):21-6. PMID: 15620409.
- [animal] Matsumoto Y, et al. "Galanin-like peptide stimulates food intake in the rat." Neurosci Lett, 2002;322(1):67-9. PMID: 11958845.
- [animal] Matsumoto H, et al. "Stimulation effect of galanin-like peptide (GALP) on luteinizing hormone-releasing hormone-mediated luteinizing hormone (LH) secretion in male rats." Endocrinology, 2001;142(8):3693-6. PMID: 11459819.
- [mechanism] Juréus A, et al. "Galanin-like peptide (GALP) is a target for regulation by leptin in the hypothalamus of the rat." Endocrinology, 2000;141(7):2703-6. PMID: 10875277.
- [mechanism] Seth A, et al. "Effects of galanin-like peptide on food intake and the hypothalamo-pituitary-thyroid axis." Neuroendocrinology, 2003;77(2):125-31. PMID: 12624534.
- [other] UniProt Q9UBC7 (GALP_HUMAN), read November 6, 2026: galanin-like peptide is the product of the GALP gene, a 60-amino-acid hypothalamic neuropeptide that shares a 13-residue stretch with galanin and activates the galanin receptors (GalR1-3), with a reported preference for GalR2. https://www.uniprot.org/uniprotkb/Q9UBC7/entry
- [other] Galanin-like peptide was isolated from porcine hypothalamus in 1999 on the basis of its ability to activate the galanin receptor GalR2, and later identified in rat and human; its biology is set out in the energy-homeostasis-and-reproduction review carded on this page (read November 6, 2026).
- [other] US FDA, Drugs@FDA and the drug label endpoint (openFDA), searched November 6, 2026: no application and no label record for galanin-like peptide. It is an endogenous human peptide, not a registered drug; FDA GSRS and ChEMBL hold no substance record for it.
Sources & Citations
The six studies carded above were read from their PubMed records on November 6, 2026. Identity comes from UniProt (Q9UBC7, gene GALP); galanin-like peptide’s 60-amino-acid structure, its homology with galanin, its galanin-receptor activity and its leptin-linked roles in feeding, energy balance, reproduction and the thyroid axis are from the reviews and studies carded here; the absence of US approval and of a drug substance record from Drugs@FDA, openFDA, FDA GSRS and ChEMBL was checked the same day. Grey Peptides sells nothing and links to no vendor.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.