Peptide YY (1-36)

Summary

PYY(1-36) is the untruncated, biologically active precursor form of Peptide YY released postprandially from intestinal L-cells. It circulates at lower levels than PYY(3-36) due to rapid cleavage by dipeptidyl peptidase-IV (DPP-IV). It plays roles in the 'ileal brake' phenomenon, slowing gastrointestinal transit, and has complex, mixed effects on appetite via multiple NPY receptor subtypes. It is primarily a research tool and endogenous biomarker rather than a therapeutic agent.

Mechanism of Action

Peptide YY (1-36) is the full-length form of PYY secreted by L-cells of the distal gut. It acts as an agonist at Y1, Y2, Y4, and Y5 neuropeptide Y receptors. Unlike PYY(3-36), it does not show selectivity for Y2 receptors and has broader receptor activity. It modulates gastrointestinal motility, reduces gastric acid secretion, and has complex effects on appetite regulation — generally considered less potently anorectic than PYY(3-36) because of additional Y1/Y5 receptor activity which can stimulate feeding.

Routes of Administration

Goals & Uses

• Pancreatic exocrine secretion inhibitionGastrointestinalLow
• Obesity research biomarkerResearch / MetabolicModerate
• Gastrointestinal motility reduction (ileal brake)GastrointestinalModerate
• Appetite and satiety modulationMetabolic / EndocrineModerate

Contraindications

• Known hypersensitivity to PYY or excipientsImmunologicHigh
• Clinical therapeutic use outside approved trialsRegulatoryHigh

Adverse Effects

• Injection site reactionsLocalUncommon
• Reduced gastric motility / delayed gastric emptyingGastrointestinalCommon
• HypotensionCardiovascularUncommonLow blood pressure
• NauseaGastrointestinalCommonFeeling of sickness or urge to vomit

Drug Interactions

• DPP-IV inhibitors (e.g., sitagliptin, saxagliptin)Moderate
• Neuropeptide Y receptor antagonistsModerate

Population Constraints

• Pediatric populationsAgeRelative
• Patients with severe gastrointestinal dysmotilityGastrointestinalRelative
• Pregnant womenReproductiveRelative

Regulatory Status

• European UnionUnapprovedNo EMA approval; research use only.
• United StatesUnapprovedNo FDA approval; used only in research and clinical investigational contexts.
• United KingdomUnapprovedNo MHRA approval; utilized in academic and clinical research settings.

Not approved by the FDA, EMA, or any major regulatory authority as a therapeutic agent. Used exclusively in preclinical and clinical research settings to study gut-brain axis signaling and energy homeostasis.

Evidence & Sources

No sources recorded yet.