Evidence memo / Metabolic & weight

Oxyntomodulin

Also: OXM · glucagon/GLP-1 gut hormone

Oxyntomodulin is a natural gut hormone that activates both the GLP-1 and glucagon receptors, reducing appetite and raising energy use. It is not an approved drug, but its dual action is the inspiration for the glucagon/GLP-1 dual-agonist obesity drugs now in development. Human studies of oxyntomodulin itself are short and small. The Watchlist boundary is separating its real appetite biology and its role as a template from the idea that oxyntomodulin itself is a finished treatment.

Early human signalEarly human signalInvestigationalSafety / regulatory watch

The verdict

Our read at a glance.

Whether oxyntomodulin's natural dual GLP-1 and glucagon activity translates into a usable weight-loss treatment, versus serving mainly as the template for engineered dual agonists.

The signal
Short human studies show oxyntomodulin reduces appetite and food intake and modestly affects weight. Its very short duration in the body limits it as a drug, and most development has shifted to longer-acting dual agonists modeled on it. It is not approved.
The unknown
Whether oxyntomodulin itself, or longer-acting versions, can deliver meaningful weight loss with acceptable tolerability beyond what the engineered dual agonists already show.
Our read
A real appetite hormone that mainly matters as the blueprint for dual agonists, not as a finished drug itself. Oxyntomodulin reduces appetite in short studies, but its rapid breakdown means the action has moved to the engineered glucagon/GLP-1 drugs modeled on it.

The mechanism

How it works.

Oxyntomodulin is a gut hormone made in the same intestinal cells as GLP-1 and released after eating. It is a weak agonist at two receptors at once: the GLP-1 receptor, where it curbs appetite and slows stomach emptying, and the glucagon receptor, where it nudges energy expenditure and liver fat handling up. Combining appetite suppression with higher energy use is exactly the logic behind the engineered glucagon/GLP-1 dual agonists, but oxyntomodulin itself is broken down within minutes, so it has not become a drug on its own.

Safety & regulatory boundary

The consequential part.

Oxyntomodulin is not an approved drug. Human studies are short and small, and its rapid breakdown limits it as a treatment. Research-labeled or compounded oxyntomodulin is not an approved product, and its biology does not establish a proven weight-loss therapy. The engineered dual agonists it inspired are separate products with their own evidence.

What's next

What we're watching.

Longer-acting oxyntomodulin analogs, and how the engineered dual agonists it inspired perform in late-stage trials.

Context

Why this is discussed.

Oxyntomodulin is the natural model for the glucagon/GLP-1 dual agonists that are now among the most closely watched obesity drugs, which keeps interest in the original hormone high.

The evidence base

20 cited references.

Indexed literature (PubMed)12

Gut hormones and appetite regulation

Hong SH et al. · Curr Opin Endocrinol Diabetes Obes · 2024

Enteroglucagon

Holst JJ · Annu Rev Physiol · 1997

Oxyntomodulin - past, present and future

Holst JJ et al. · Peptides · 2025

Oxyntomodulin: Actions and role in diabetes

Holst JJ et al. · Peptides · 2018

Gastrointestinal satiety signals

Chaudhri OB et al. · Annu Rev Physiol · 2008

Gastrointestinal satiety signals

Chaudhri OB et al. · Int J Obes (Lond) · 2008

Combination Therapies for Obesity

Camilleri M et al. · Metab Syndr Relat Disord · 2018

Proglucagon-Derived Peptides as Therapeutics

Lafferty RA et al. · Front Endocrinol (Lausanne) · 2021

The role of oxyntomodulin and peptide tyrosine-tyrosine (PYY) in appetite control

Wynne K et al. · Nat Clin Pract Endocrinol Metab · 2006

Keep reading

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