Cite this answer
Peptide YY: quick citable summary
Peptide YY is listed by PeptaHub as a weight loss peptide with a research only legal-status classification. The page summarizes mechanism, research context, common routes, safety notes, and references for writers and AI answer engines.
PeptaHub. “Peptide YY: Mechanism, Research Context, Safety.” peptahub.com, 2026. https://peptahub.com/peptides/peptide-yy. Licensed CC BY 4.0.
License: Creative Commons Attribution 4.0 International. Link back to https://peptahub.com/peptides/peptide-yy.
What is Peptide YY?
Peptide YY is a 36-amino acid endogenous gut hormone released after meals that acts as a potent satiety signal through hypothalamic Y2 receptors. Combined with GLP-1, it produces additive appetite suppression, positioning PYY combination therapies as next-generation anti-obesity candidates.
Overview
Peptide YY (PYY) is a 36-amino acid endogenous gut hormone released from L-cells of the distal intestine in proportion to caloric intake. PYY acts as a potent satiety signal, suppressing appetite through Y2 receptor activity in the hypothalamus. It is co-released with GLP-1 following meals, and the two hormones have complementary and sometimes synergistic appetite-suppressing effects. PYY is being explored as a weight loss therapeutic alongside or as an alternative to GLP-1 receptor agonists.
Mechanism of action
PYY exerts its primary satiety effect through binding to neuropeptide Y (NPY) Y2 receptors in the arcuate nucleus of the hypothalamus. Y2 receptor activation inhibits NPY/AgRP orexigenic neurons, reducing the drive to eat. The predominant circulating form PYY3-36 (generated by dipeptidyl peptidase-IV cleavage of PYY1-36) is highly selective for Y2 over Y1 receptors, making it more potent as a satiety signal with fewer peripheral effects. PYY also slows gastric emptying via the 'ileal brake' mechanism — reducing GI motility to optimize nutrient absorption. Peripheral PYY crosses the blood-brain barrier via active transport and acts directly on brainstem areas including the nucleus tractus solitarius. When co-administered with GLP-1 in short human infusion studies, the reduction in energy intake is greater than with either hormone alone.
Reported study ranges
| Purpose | Route | Reported range | Frequency | Notes |
|---|---|---|---|---|
| Appetite suppression (IV infusion, research setting) | intravenous | 0.3–0.8 pmol/kg/min | acute infusion over 90-120 minutes | Research protocol only. Higher doses associated with nausea. No validated subcutaneous human protocol established. |
Reported ranges are for research context only. Consult a qualified healthcare professional before using any peptide.
Convert Peptide YY research-range units
Need to convert mg to mcg, dose volume, or U-100 syringe units? Use the peptide dose unit converter for educational calculation support.
Research summary
The landmark human work is Batterham et al. (Nature 2002), which showed that infusing normal postprandial concentrations of PYY3-36 significantly decreased appetite and reduced food intake by 33% over 24 hours, and that the anorectic effect was absent in Y2 receptor-null mice — establishing the Y2R as the required mediator. Neary et al. (Endocrinology 2005) co-infused PYY3-36 and GLP-1(7-36) at 0.4 pmol/kg/min each for 120 minutes in 10 lean fasted volunteers and found energy intake from a buffet meal reduced by 27%, significantly below either hormone alone, supporting an additive rather than merely overlapping effect. Human trials of intranasal PYY3-36 produced inconsistent appetite suppression, partly due to nausea at effective doses. PYY levels are lower in people with obesity and rise after bariatric surgery, which is the basis for the hypothesis that it contributes to post-surgical weight loss. Combination approaches targeting several satiety hormones at once are an active development strategy, but no PYY analog has completed a Phase 3 obesity trial.[1][2][3][4][5][6][7]
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 Peptide YY for synergistic effects.
Legal status
No FDA-approved PYY therapeutic exists as of 2026. PYY analogs are in active pharmaceutical development. Research use only for synthetic forms.
Sourcing & access
Research compound
Peptide YY 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
Peptide YY (PYY) is a 36-amino acid gut hormone released from L-cells of the distal intestine in proportion to caloric intake. It suppresses appetite through Y2 receptor activity in the hypothalamus and is co-released with GLP-1 following meals.
PYY3-36 (the predominant circulating form) binds Y2 receptors in the arcuate nucleus, inhibiting NPY/AgRP orexigenic neurons to reduce the drive to eat. It also slows gastric emptying via the ileal brake mechanism and crosses the blood-brain barrier via active transport.
Nausea is the primary dose-limiting side effect at therapeutic doses. Other side effects include vomiting, headache, and GI discomfort. No FDA-approved PYY therapeutic exists as of 2026. Intranasal delivery attempts produced inconsistent results partly due to nausea.
PYY and GLP-1 are co-secreted from intestinal L-cells and act through different receptors. In 10 lean volunteers, a 120-minute co-infusion of both at 0.4 pmol/kg/min reduced buffet-meal energy intake by 27 percent, significantly more than either hormone alone, which is why the effect is described as additive. PYY levels are lower in people with obesity and rise after bariatric surgery. No PYY analog has completed a Phase 3 obesity trial, so this remains a development strategy rather than an available treatment.
Research references
- Evolution of peptide YY analogs for the management of type 2 diabetes and obesityPubMed
- Gut peptide regulation of food intake - evidence for the modulation of hedonic feedingPubMed
- The satiety hormone peptide YY as a regulator of appetiteReview
- Emerging therapeutic potential for peptide YY for obesity-diabetesReview
- Proteins and Peptides from Food Sources with Effect on Satiety and Their Role as Anti-Obesity Agents: A Narrative ReviewReview
- Gut hormone PYY(3-36) physiologically inhibits food intakePubMed
- Peptide YY3-36 and glucagon-like peptide-1(7-36) inhibit food intake additivelyPubMed