Quick summary
Obestatin is a 23-amino acid peptide from the ghrelin gene, initially reported as a ghrelin antagonist. It is now one of the most contested peptides in metabolic endocrinology, with its receptor and mechanism still disputed.
Overview
Obestatin is a 23-amino acid peptide encoded by the same preproghrelin gene that produces ghrelin, discovered in 2005. Initially described as a ghrelin antagonist that suppressed food intake and gastric motility, subsequent research yielded conflicting results, making obestatin one of the most contested peptides in metabolic endocrinology. Current evidence suggests it functions as an independent multi-functional hormone rather than a simple ghrelin antagonist.
Mechanism of action
Obestatin was originally reported to bind GPR39 (an orphan GPCR) and oppose ghrelin's orexigenic actions. However, multiple independent groups failed to confirm GPR39 binding or a consistent anorexigenic effect. More recent studies indicate obestatin signals through pathways including GLP-1 receptor cross-talk and phospholipase C activation. It may regulate glucose metabolism, pancreatic beta-cell survival, and smooth muscle contractility independently of ghrelin. The definitive receptor and downstream cascade remain contested in the literature.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| metabolic / satiety research (animal) | intravenous | 10–100 nmol/kg | per experimental protocol |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
The 2005 Science paper reporting obestatin's discovery generated immediate interest but proved difficult to replicate. Multiple groups reported absence of satiety effects or GPR39 binding. Current research pivots toward obestatin's potential roles in cell survival (particularly pancreatic islets and cardiomyocytes), gastric adaptation, and reproductive function. Plasma obestatin levels are altered in obesity, polycystic ovary syndrome, and Prader-Willi syndrome. No therapeutic applications have advanced to clinical trials.[1][2][3][4]
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 Obestatin for synergistic effects.
Legal status
Obestatin is available for laboratory research use only with no approved clinical applications.
Sourcing & access
Research compound
Obestatin 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
Obestatin is a 23-amino acid peptide encoded by the preproghrelin gene, discovered in 2005. Initially described as a ghrelin antagonist that suppressed food intake, subsequent research yielded conflicting results, and current evidence suggests it functions as an independent multi-functional hormone rather than a simple ghrelin antagonist.
Obestatin's mechanism remains contested. The original GPR39 receptor binding report was not replicated by multiple independent groups. More recent studies indicate signaling through GLP-1 receptor cross-talk and phospholipase C activation, potentially regulating glucose metabolism, pancreatic beta-cell survival, and smooth muscle contractility.
Obestatin's safety profile is not well characterized. Animal studies report reduced gastric motility at high doses. No therapeutic applications have advanced to human clinical trials, and it remains a research-only compound.
The 2005 Science paper reporting obestatin's discovery generated immediate interest but proved difficult to replicate. Multiple groups reported absence of satiety effects or GPR39 binding, making it one of the most disputed peptide discoveries in recent metabolic endocrinology.
Research references
- Obestatin: a ghrelin-associated peptide inhibiting food intake and weight gainPubMed
- Obestatin and ghrelin: opposing effects on energy balance and metabolismPubMed
- Obestatin effects on pancreatic function and insulin secretionPubMed
- Obestatin and GPR39 receptor: binding pharmacology and cardiovascular implicationsPubMed