Weight & metabolic
Peptide YY
PYY 3-36, PYY
Peptide YY is a gut hormone released from intestinal L cells after a meal, and one of the principal endogenous satiety signals. PYY 3-36 is its active circulating fragment. It has been investigated extensively for obesity but no PYY-based drug has reached approval.
Also known as: PYY 3-36, PYY3-36, peptide tyrosine tyrosine
- Status
- Peptide YY is a research compound and not approved by the FDA for human use.
- Evidence
- Early human data. Only small or early-phase studies in people so far.
- Half-life
- Approximately 8 to 10 minutes for the native peptide.
- How it's taken
- Intravenous infusion in the research setting
- Mechanism
- Metabolic (non-incretin)
How Peptide YY works
PYY 3-36 is produced when dipeptidyl peptidase-4 cleaves two residues from full-length PYY, which shifts its receptor selectivity from broad NPY-receptor activity to selective Y2 receptor agonism. Y2 receptors on hypothalamic arcuate neurons are inhibitory autoreceptors on NPY/AgRP appetite-stimulating neurons, so PYY 3-36 suppresses the drive to eat. It is co-secreted with GLP-1 from the same cells, which is why the two rise together after eating and after bariatric surgery.
What research has looked at
- Infusion studies in humans reliably reduce food intake at a subsequent meal, in both lean and obese participants — one of the more reproducible findings in appetite research.
- The marked rise in postprandial PYY after Roux-en-Y gastric bypass is considered part of why that operation suppresses appetite, beyond mechanical restriction.
- It acts through a receptor pathway distinct from GLP-1, which is why PYY analogues are being developed as combination partners rather than replacements.
Evidence level: Early human data. Only small or early-phase studies in people so far. These are areas studied or reported, not promised effects.
Reported side effects and risks
- Nausea is dose-limiting and was the principal obstacle in clinical development — the doses that reliably suppress appetite substantially overlap with those that cause nausea.
- Native PYY has a very short half-life and requires continuous infusion, which is why development has focused on engineered long-acting analogues.
- No PYY-based product has been approved by any regulator for obesity or any other indication.
- Intranasal formulations were tried and failed to produce reliable absorption.
- Material sold as PYY is research chemical supply with unverified identity, purity, sterility and dose accuracy.
Sources
- PubMed research on PYY 3-36 satiety food intake · NIH · National Library of Medicine
- DrugBank record for peptide YY · DrugBank
- Active clinical trials for peptide YY · U.S. National Library of Medicine
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Peptide YY FAQ
What is Peptide YY?
Peptide YY is a gut hormone released from intestinal L cells after a meal, and one of the principal endogenous satiety signals. PYY 3-36 is its active circulating fragment. It has been investigated extensively for obesity but no PYY-based drug has reached approval.
How does Peptide YY work?
PYY 3-36 is produced when dipeptidyl peptidase-4 cleaves two residues from full-length PYY, which shifts its receptor selectivity from broad NPY-receptor activity to selective Y2 receptor agonism. Y2 receptors on hypothalamic arcuate neurons are inhibitory autoreceptors on NPY/AgRP appetite-stimulating neurons, so PYY 3-36 suppresses the drive to eat. It is co-secreted with GLP-1 from the same cells, which is why the two rise together after eating and after bariatric surgery.
Is Peptide YY FDA approved?
No. Peptide YY is a research compound and not approved by the FDA for human use. Evidence level: early human data. Only small or early-phase studies in people so far.
What is the half-life of Peptide YY?
Reported half-life: Approximately 8 to 10 minutes for the native peptide.
How is Peptide YY taken?
Intravenous infusion in the research setting.
What side effects have been reported with Peptide YY?
Reported in the sources: Nausea is dose-limiting and was the principal obstacle in clinical development — the doses that reliably suppress appetite substantially overlap with those that cause nausea; Native PYY has a very short half-life and requires continuous infusion, which is why development has focused on engineered long-acting analogues; No PYY-based product has been approved by any regulator for obesity or any other indication; Intranasal formulations were tried and failed to produce reliable absorption; Material sold as PYY is research chemical supply with unverified identity, purity, sterility and dose accuracy.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.