Beyond GLP-1: Metabolites in snake blood show weight loss potential
Key takeaways
- Scientists identified pTOS, a gut-microbiota-derived metabolite in python blood, that suppresses appetite and drives weight loss in mice without GLP-1-like side effects.
- pTOS levels surged about 1,000-fold after pythons’ large infrequent meals; in mice, high-dose pTOS acted on the hypothalamus to reduce food intake.
- The team founded Arkana Therapeutics, hoping to develop pTOS-inspired analogs as next-generation therapies for obesity and sarcopenia.
Research has discovered an appetite-suppressing compound in python blood, allowing them to consume large meals while remaining metabolically healthy for long periods without needing to consume more. They believe that para-tyramine-O-sulfate (pTOS) could inspire chemically synthesized analogs to inspire weight loss and sarcopenia therapies.
Researchers from the US-based Colorado Boulder, Stanford, and Baylor universities believe pTOS-based weight loss therapies can also prevent side effects from current drugs like GLP-1, such as nausea.
In the study, they found that pTOS, which is produced by the python’s gut bacteria, caused weight loss in mice without gastrointestinal issues.
The team has also formed a start-up, Arkana Therapeutics, to commercialize their findings for potential therapeutic applications. They are planning to investigate the metabolites’ effects on humans and explore other types identified in pythons that could potentially help against age-related muscle loss.

Understanding metabolism in extremes
Senior author Leslie Leinwand has studied pythons for over two decades and explains that they can grow as large as a telephone pole, swallow an antelope whole, and go months or even years without eating. Despite this, they maintain a healthy heart and muscle mass.
Leinwand and graduate student Skip Maas observe Maas’ two pet pythons, Gaius and Agrippina.“This is a perfect example of nature-inspired biology. You look at extraordinary animals that can do things that you and I and other mammals can’t do, and you try to harness that for therapeutic interventions.”
Leinwand, also a professor of Molecular, Cellular and Developmental Biology at the University of Colorado, shares that her research shows python hearts expand 25%, and metabolism speeds up 4,000-fold following post-meal hours to help digestion.
She teamed with Jonathan Long, associate professor of pathology at Stanford University, to understand how metabolic byproducts in the blood, or metabolites, play a role. Recently, his lab examined the blood of racehorses to learn how they endure sprints.
“If we truly want to understand metabolism, we need to go beyond looking at mice and people and look at the greatest metabolic extremes nature has to offer,” believes Long.
Appetite suppressant in mice
For the new study in Natural Metabolism, the team examined blood sampled from ball pythons and Burmese pythons immediately after meals. They were fed once every 28 days.
The researchers pinpointed 208 metabolites that significantly rose after the pythons ate, where pTOS stood out, soaring 1,000-fold.
Additional studies at Baylor University revealed that high doses of pTOS in obese or lean mice had an effect on the hypothalamus, which is the appetite center of the brain. This triggered weight loss without affecting digestion, muscle loss, and energy.
“We’ve basically discovered an appetite suppressant that works in mice without some of the side effects that GLP-1 drugs have,” adds Leinwand.
Arkana Therapeutics may turn extreme python metabolism into potential weight-loss and anti-sarcopenia innovations.pTOS is not naturally present in mice but is found in human urine in low levels and increases slightly after a meal. The researchers explain that since previous research has been carried out in mice or rats, pTOS has been overlooked.
Learning from nature to commercialization
Leinwand points out that the GLP-1 drugs were inspired by another reptile, the Gila monster, whose venom contains a similar hormone to GLP-1. Now, although these drugs are widely used, studies show that almost half of the users stop taking them within a year. “We believe there is still room for therapeutic growth in this market,” she adds.
The team’s Arkana Therapeutics seeks to commercialize some of the lessons they are learning from pythons. They hope chemically synthesized analogs of the rare pTOS could be turned into therapies to help human health, going beyond weight loss.
The team is also focused on sarcopenia, which impacts almost everyone as they get older and especially affects people with health issues that hinder them from exercising. There are no therapies to stop or reverse sarcopenia. However, Leinwand believes the snakes can offer insights for a new solution.
In future research, the team hopes to explore how pTOS works in people and catalogue the function of the other metabolites that increase after pythons eat. Some metabolites the researchers identified in their study soared by 500–800%.
“We’re not stopping with just this one metabolite,” says Leinwand. “There’s a lot more to be learned.”
Recently, on World Obesity Day 2026, Nutrition Insight spoke with experts from Beneo, Gnosis by Lesaffre, and Sanroo and explored the future of weight management in the supplement and nutraceutical industry.
Start-up innovations in these spaces include complementary products to support GLP-1 users, addressing issues like gut health and protein absorption. The rise of these medications has created opportunities for innovative secondary markets, including solutions for energy levels, gut health, and nutrient-dense foods.
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