From Venomous to Valuable: The Role of the Gila Monster in the Development of Ozempic®.
- GEAS Brasil
- 22 hours ago
- 4 min read
Ozempic®, Mounjaro®, and Wegovy® – much is known about the injectable medications used in the treatment of obesity and diabetes; however, little is known about the animal behind this pharmaceutical phenomenon, the Gila monsters (Heloderma spp.). These reptiles belong to the family Helodermatidae and the order Squamata, with five recognized species: Heloderma alvarezi, H. charlesbogerti, H. exasperatum, H. horridum, and H. suspectum. Their name refers to the Gila River region, where the species occurs, spanning the southwestern United States and northern Mexico. They are robust lizards that can reach up to 50 centimeters in length, characterized by alternating black bands or blotches and pinkish
tones, along with distinctive scales. Their carnivorous diet consists of small mammals, eggs, and birds, and both their tail and abdominal region store fat reserves that provide energy during colder months. Gila monsters are among the few venomous lizards in the world, capable of delivering prolonged bites while venom is injected into their prey. This neurotoxic
venom is produced by glands located in the lower jaw and conducted to the teeth through
grooves. Despite this efficient envenomation mechanism, serious accidents involving humans
are infrequent, and fatalities are rare (Koludarov et al., 2014).
Figura 1. Heloderma suspectum, popular known as Gila Monster. Source: Suspectum Do Monstro/Heloderma De Gila Foto
de Stock - Imagem de arizona, mojave: 28056064
But when did the Gila monster begin to be studied? In the 1980s, American biochemist John Pisano, who had a particular interest in herpetology, worked with Gila monster venom alongside gastroenterologist Jean-Pierre Raufman. In the following decade, Pisano, Raufman, and endocrinologist John Eng succeeded in identifying a hormone-like molecule, which they named exendin-4. This molecule stimulates insulin secretion by acting on the same receptor as GLP-1 (Glucagon-like peptide-1). During their research, they discovered that exendin-4 was not rapidly metabolized by the body and could, therefore, be useful as a treatment for diabetes. Despite these promising effects, pharmaceutical companies were reluctant to distribute a compound derived from lizard venom, which initially hinderedthe drug’s patenting process. Nevertheless, Eng and Raufman persuaded the American company Amylin Pharmaceuticals© to patent the product, and through this corporate partnership, the effects of exendin-4 in humans were confirmed. In 2005, the FDA (Food and Drug Administration) approved exendin-4 for commercial distribution under the name Byetta®. This development laid the foundation for the refinement and widespread use of drugs such as Ozempic®.
In this context, the venom of the Gila monster became the focus of extensive research within the pharmaceutical industry. Exendin-4, isolated from the venom of Heloderma suspectum, is a peptide agonist of the glucagon-like peptide-1 (GLP-1) receptor that stimulates insulin secretion. Furthermore, it has been clinically employed in the treatment of type 2 diabetes and to enhance plasma insulin secretion (Deane, A. M. et al., 2010). In addition, the venom of this reptile has also been categorized according to other proteomic characteristics of pharmaceutical relevance, as shown in the following table:
Fig 2. Table of Environmental Covariates Used for the Adequate Habitat Modeling of Gila Monsters in the Mojave Desert
Employing Ensemble Modeling. All layers were scaled to a 250 m resolution for habitat modeling. Source:
<https//doi:10.1002/ece3.71008>
Fig 3. The Butantan Institute’s "Animal of the Month" booklet of environmental education activities. August 2020 edition onthe Gila monster. Source: Butantan Institute Site: MONSTRO-DE-GILA
Despite their great medical relevance, these animals are classified as “Near Threatened” on the IUCN Red List (International Union for Conservation of Nature), due to habitat degradation and trafficking of the species. However, precise quantitative assessments of their populations are difficult to obtain because of their subterranean habits, which greatly hinder specimen research and the estimation of accurate geographic distribution and population size (Hromada, S. J. et al., 2025). In Brazil, two individuals of Heloderma spp. were illegally brought into the country, later rescued by IBAMA, and subsequently transferred to the Butantan Institute, where they currently live in the Biological Museum. The Institute also develops environmental education materials aimed at helping children better understand these animals and showing that, despite their name, they are not monsters.
The relationship between the Gila monster and advances in the treatment of type 2 diabetes and obesity illustrates how little-known species may hold valuable solutions to human health challenges. Nevertheless, the scarcity of studies on their ecophysiology and distribution, combined with habitat loss, highlights an even greater risk: the possibility of losing such species before fully understanding their potential. This example underscores that, by threatening biodiversity, we endanger not only ecological balance but also scientific discoveries that could transform medicine, biotechnology, and other fields of knowledge.
Thus, it is urgent to recognize that each species lost also represents an entire realm of opportunities that we may never come to know.
Author/s: Denise Pereira Gomes Figueiredo - GEAS Brazil’s Trainee of Languages and
Accessibility
Review: Iago Junqueira - GEAS BRASIL partner by The Wild Place
Wild Panel of August/2025.
BIBLIOGRAPHICAL REFERENCES:
KOLUDAROV , I.; JACKSON, T. N.; SUNAGAR, K.; NOUWENS, A.; HENDRIKX, I.;
FRY , B. G. “Fossilized venom: the unusually conserved venom profiles of Heloderma species
(beaded lizards and gila monsters).” Toxins vol. 6,12 3582-95. 22 Dec. 2014,
doi:10.3390/toxins6123582
DEANE, A. M.; CHAPMAN, M. J.; HOROWITZ, M. The therapeutic potential of a
venomous lizard: the use of glucagon-like peptide-1 analogues in the critically ill. Critical
Care, v. 14, n. 5, p. 1004, 2010.
HROMADA, S. J.; JONES, J. L., STALKER, J. B.; WOOD, D. A.; V ANDERGAST, A. G.;
Tracy, C. R., GIENGER, C. M., & NUSSEAR, K. E. (2025). Climate and Dispersal Ability
Limit Future Habitats for Gila Monsters in the Mojave Desert. Ecology and Evolution, v. 15,
n. 3, mar. 2025. doi:10.1002/ece3.71008
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NATIONAL INSTITUTE ON AGING. Exendin-4: From lizard to laboratory...and beyond.
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