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Research information only. Not medical advice. 18+ only. Not FDA-approved for human therapeutic use.

PYY 3-36 (Peptide YY)

Also known as: Peptide YY 3-36, PYY(3-36), Peptide YY, PYY 1-36

Gut-derived satiety peptide hormone; neuropeptide Y family member; enteroendocrine hormone

Research chemicalLast updated: October 10, 2026Based on 3 peer-reviewed studies
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What it is

PYY 3-36 is a gut hormone that researchers study as a potential treatment for obesity and appetite suppression. It is released naturally from the intestines after eating and signals the brain to feel full, reducing how much food a person wants to eat. It is not FDA-approved, has had failed drug development attempts, and remains a research compound only.

The scientific side

PYY 3-36 is the primary circulating truncated form of Peptide YY, produced when the enzyme dipeptidyl peptidase IV (DPP-IV) cleaves two amino acids from the full PYY 1-36 molecule after it is secreted from L-cells in the distal gut (ileum, colon, and rectum) following a meal. Unlike the full-length form, PYY 3-36 selectively activates the Y2 receptor subtype on nerve cells, which reduces appetite. Through Y2 receptor activation in brain feeding-control regions, PYY 3-36 reduces the activity of hunger-promoting nerve cells and enhances signals from fullness-promoting nerve cells, leading to decreased food intake. Obese individuals have lower fasting and after-meal PYY levels compared to lean people, suggesting a hormonal deficiency that may contribute to difficulty feeling full. Crucially, obesity does not appear to cause resistance to PYY 3-36 — exogenous infusion reduces food intake similarly in both lean and obese subjects (approximately 30–36%). PYY 3-36 also slows stomach emptying, reducing the rate at which nutrients reach the small intestine, which prolongs the sensation of fullness. Bariatric surgeries such as Roux-en-Y gastric bypass dramatically increase postprandial PYY release, and this elevation is thought to be a key mechanism behind the appetite-suppressing benefits of those procedures. The hormone also interacts with other gut hormones — including GLP-1, ghrelin, and cholecystokinin — as part of an integrated gut-brain satiety system. The vagus nerve appears to be required for physiological, meal-related PYY signaling but may not be needed for the appetite-suppressing effects of pharmacological doses. (PMIDs: 15777187, 16756746, 15544446, 22000927, 17148749, 18441153, 38546831)

Class: Gut-derived satiety peptide hormone; neuropeptide Y family member; enteroendocrine hormone

Administration & storage

Administration
Intravenous infusion (IV) — used in all human clinical studiesIntraperitoneal injection — used in rodent studies onlySubcutaneous (nasal/lingual delivery investigated in clinical trialse.g. NCT05110664but not established as effective route)
Storage
Research-grade PYY 3-36 peptide is typically stored lyophilized at -20°C or lower, protected from light and moisture. Reconstituted solutions should be used immediately or stored on ice for short periods. No community storage guidance has been established.
Cautions
Nausea is the primary dose-limiting side effect; occurred at 0.8 pmol/kg/min IV infusion and caused most participants in that dose arm to discontinue (17148749),Reduced well-being and increased heart rate observed at high IV doses (17148749),Elevated free fatty acids and postprandial insulin concentrations at high doses (17148749),Tendency toward reduced energy expenditure at high dose in one study (17148749),No established safe self-use dose; all human data comes from clinical research settings with medical supervision

Legal & regulatory status

US FDA

Not FDA-approved as a therapeutic agent. Development as a weight-loss drug (notably by Nastech Pharmaceutical) was discontinued after early-phase clinical setbacks including nausea at effective doses and poor oral…

WADA

Not stated in reviewed literature — requires manual verification

Health Canada

Not stated in reviewed literature — requires manual verification