Oxyntomodulin
Also known as: OXM, glucagon-37, proglucagon 33-69, GLP-1R/GCGR dual agonist
Endogenous proglucagon-derived peptide hormone; gut incretin; dual GLP-1 receptor / glucagon receptor (GLP-1R/GCGR) co-agonist; anorexigenic gut hormone
What it is
Oxyntomodulin is a gut hormone gaining attention among people looking to manage weight and blood sugar naturally. Released after meals, it suppresses appetite, accelerates calorie burning, and improves glucose control by acting on two receptors at once. Researchers are developing long-acting analogs as next-generation obesity and diabetes therapies.
The scientific side
oxyntomodulin (OXM) is a 37-amino acid peptide derived post-translationally from the proglucagon precursor (proglucagon residues 33–69) through tissue-specific processing by prohormone convertase 1/3 in enteroendocrine L-cells of the small intestine and colon. OXM shares its first 29 amino acids with glucagon and contains the additional eight-residue C-terminal extension (octapeptide) that distinguishes it from glucagon. This structural feature confers dual receptor agonism: OXM binds and activates both the glucagon-like peptide-1 receptor (GLP-1R) and the glucagon receptor (GCGR), though with lower intrinsic potency at each receptor compared to their native ligands GLP-1 and glucagon individually. Both receptors are class B G protein-coupled receptors that signal primarily through Gs-mediated adenylyl cyclase activation, elevating intracellular cyclic AMP (cAMP). GLP-1R activation in the hypothalamic arcuate nucleus is critical for OXM's appetite-suppressing (anorexigenic) effects, as demonstrated by studies showing that central injection of OXM reduces food intake and body weight, and that pre-treatment with the GLP-1R antagonist exendin 9-39 attenuates these effects. GLP-1R activation in pancreatic beta-cells stimulates glucose-dependent insulin secretion, an effect confirmed with native IV OXM in crossover studies in obese subjects with and without type 2 diabetes. OXM simultaneously suppresses the orexigenic hormone ghrelin: an IV infusion of native OXM at 3.0 pmol/kg/min produced a 44% reduction in preprandial ghrelin relative to postprandial nadir, amplifying its satiety signaling. GCGR activation by OXM in the central nervous system and brown adipose tissue increases thermogenesis, with intracerebroventricular OXM stimulating interscapular brown adipose tissue activity and upregulating uncoupling protein-1 (UCP-1) and PGC-1α gene expression in a GLP-1R-dependent manner. In the gastrointestinal tract, OXM delays gastric emptying during the early postprandial period while accelerating transit in the distal intestine, and potently inhibits fed-pattern myoelectrical activity in the small intestine — effects that may further reduce energy intake by slowing nutrient absorption. OXM secretion is proportional to meal caloric content and is markedly elevated after bariatric procedures such as Roux-en-Y gastric bypass (RYGB).
Class: Endogenous proglucagon-derived peptide hormone; gut incretin; dual GLP-1 receptor / glucagon receptor (GLP-1R/GCGR) co-agonist; anorexigenic gut hormone
Administration & storage
- Administration
- Intravenous infusion (continuousrate-controlled pump) — used in acute mechanistic human studies (PMID: 1455744329545266)Subcutaneous injection — used in the Wynne et al. 2005 weight loss RCT; self-administered by subjects (PMID: 16046306)Continuous subcutaneous infusion via programmable pump — used in GOP tripeptide infusion studies (PMID: 31177183)Intracerebroventricular injection — used in preclinical rodent studies to characterize central nervous system mechanisms (PMID: 22933116); not applicable to human use
- Storage
- Research-grade lyophilized oxyntomodulin peptide should be stored at −20°C in sealed vials protected from moisture and light. After reconstitution in sterile saline, solutions should be used promptly or stored at 4°C for no more than 24 hours. Freeze-thaw cycles degrade peptide integrity. No pharmaceutical-grade oxyntomodulin product with defined shelf-life and storage specifications is commercially available. Compounded preparations should follow USP <797> pharmaceutical compounding sterility standards.
- Cautions
- No FDA-approved oxyntomodulin product exists; all human use outside formal clinical trials constitutes unapproved experimental use.,The short plasma half-life (~12 minutes) of native oxyntomodulin means IV/SC infusion protocols require controlled delivery devices; bolus dosing strategies have not been validated for sustained effect.,Dual GLP-1R/GCGR agonism carries a theoretical risk of transient hyperglycemia via glucagon receptor activation, particularly at higher doses or in individuals with impaired beta-cell insulin secretory reserve; blood glucose monitoring is advisable.,Nausea and gastrointestinal discomfort are common adverse effects at higher doses of GLP-1R-active peptides; while native OXM at physiologic doses (3.0 pmol/kg/min IV) did not cause nausea in early studies, dual agonist analogs at pharmacologic doses produced dose-dependent GI adverse events.,Heart rate elevation has been documented with OXM in mice via a GLP-1R-independent mechanism — possibly GCGR-mediated intrinsic cardiac rate increase; clinical significance in humans is unknown but warrants monitoring in individuals with cardiac conditions.,No long-term human safety data exist for native oxyntomodulin; analog trial durations have been limited to 4–12 weeks.
Legal & regulatory status
Oxyntomodulin is not FDA-approved as a drug product in the United States as of October 2026. Native oxyntomodulin has been administered only in investigational clinical trials (e.g., NCT01232244, NCT01055340,…
Oxyntomodulin is not explicitly listed by name on the current WADA Prohibited List. However, as an endogenous peptide hormone with GLP-1 receptor agonist and glucagon receptor agonist activity, it falls conceptually…
Oxyntomodulin has no approved drug product status with Health Canada. It is a naturally occurring endogenous peptide that has not been submitted for New Drug Submission (NDS) review in Canada. Dual agonist analogs…
What it's studied for
- Appetite suppression and reduction of food intake in human subjects Phase I/II human RCT
- Body weight reduction in overweight and obese individuals Phase II RCT
- Glycemic control and glucose-dependent insulin secretion — type 2 diabetes and prediabetes Phase II RCT / human mechanistic study
- Increased energy expenditure and brown adipose tissue thermogenesis Preclinical / early human mechanistic study
- Bariatric surgery — endogenous OXM as predictor and mediator of post-operative weight loss Prospective human cohort / observational
- Non-alcoholic steatohepatitis (NASH) and hepatic steatosis — investigational analog applications Preclinical / investigational
- Gut motility modulation and inhibition of postprandial small intestinal motor activity Preclinical mechanistic study
- Biomarker of visceral adiposity and insulin resistance in obesity Cross-sectional human observational study
Safety signals
- Gastrointestinal adverse events (nausea, vomiting, diarrhea) — dose-dependent with dual agonist analogs
- Transient heart rate elevation — GLP-1R-independent mechanism
- Transient hyperglycemia risk at high glucagon receptor occupancy
- Treatment discontinuation due to adverse events — dose-dependent in analog trials
- Reduced food intake and potential inadequate nutrition in vulnerable populations
- Short plasma half-life necessitating continuous delivery — device-related risk
- Elevated fasting OXM associated with insulin resistance in advanced obesity — potential endogenous dysregulation
All studies (10)
Frequently asked
Is oxyntomodulin a legal or approved peptide I can use for weight loss?
Oxyntomodulin is not FDA-approved or Health Canada-approved as a therapeutic drug for weight loss or any other indication as of October 2026. It has only been administered to humans in formally registered clinical trials under investigational conditions. There is no approved pharmaceutical formulation, standardized dose, or established safety profile for off-label or consumer use. Dual-agonist analogs inspired by oxyntomodulin's mechanism are in active Phase 2–3 development, but none has received regulatory approval. Anyone considering use should consult a licensed physician and be aware that sourcing research-grade peptides from unregulated vendors carries significant safety risks.
How does oxyntomodulin differ from GLP-1 or semaglutide?
Oxyntomodulin (OXM) and GLP-1 are both released by the same intestinal L-cells and are structurally related — they share the same first 29 amino acids. The key difference is that OXM also activates the glucagon receptor (GCGR), whereas GLP-1 and semaglutide act primarily on the GLP-1 receptor alone. This dual receptor action gives OXM the theoretical advantage of adding glucagon's thermogenic and hepatic fat-burning effects to GLP-1's appetite suppression and insulinotropic effects. However, native OXM has much lower potency at each individual receptor than semaglutide at the GLP-1R, and it degrades rapidly in plasma (half-life ~12 min). Semaglutide is a long-acting, highly potent GLP-1R agonist with extensive clinical trial data and FDA approval; OXM at present is an investigational reference molecule, not a clinical product.
What are the main side effects of oxyntomodulin?
Based on clinical research studies, native oxyntomodulin at physiologic IV doses (3.0 pmol/kg/min) did not cause nausea in early human experiments. However, synthetic analogs with stronger dual GLP-1R/GCGR agonist activity — tested in Phase 2 trials — produced dose-dependent gastrointestinal adverse events including nausea, vomiting, and diarrhea, consistent with the GLP-1R agonist drug class. Heart rate elevation has been documented in animal studies via a mechanism independent of the GLP-1 receptor, and its human significance is unknown. There are also theoretical risks of transient blood sugar fluctuations due to glucagon receptor activity, particularly at pharmacologic doses. Long-term human safety data are not available.
Can oxyntomodulin help with type 2 diabetes, not just obesity?
Research studies suggest yes, but it remains investigational for both indications. Native oxyntomodulin infusion in obese adults with type 2 diabetes improved glucose-dependent insulin secretion to an extent comparable to liraglutide (a GLP-1R agonist), and the combined GLP-1+OXM+PYY infusion produced superior glucose tolerance and glycemic variability reduction compared with Roux-en-Y gastric bypass surgery and very low-calorie diet in a small randomized trial. However, these were short-term mechanistic studies in controlled research settings, not regulatory-grade trials. No oxyntomodulin product has completed Phase 3 trials for type 2 diabetes. Approved medications with similar mechanisms (GLP-1 receptor agonists) are already available for type 2 diabetes.
What does the research say about the dosing protocol for oxyntomodulin?
There is no established clinical dosing protocol for oxyntomodulin. Research studies have used two main approaches: (1) intravenous infusion at 3.0 pmol/kg/min for acute appetite and glucose studies in a single session, and (2) subcutaneous injection three times daily, 30 minutes before each meal, for 4-week weight loss studies. A separate research group used a continuous subcutaneous infusion pump over 4 weeks to deliver a combination of gut hormones. All of these were supervised research protocols with specific eligibility criteria. Translating any of these into self-administered consumer use has not been validated, is not supported by safety data, and would constitute unapproved experimental use.