Burmese pythons have very unusual eating habits. These large snakes can eat an entire antelope and then go without food for up to a year and a half.
Scientists have now found a molecule in python blood that suppresses appetite. This discovery could lead to new weight-loss treatments. These new drugs might avoid some side effects common with current popular medications like Ozempic and Wegovy.
Python Blood and Appetite Control
Researchers published their findings in Nature Metabolism on March 19. Jonathan Long, a pathologist at Stanford University and co-author, noted that while humans are not snakes, studying these animals can reveal molecules or pathways that affect human metabolism.
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Start Your News DetoxCurrent weight-loss drugs, known as GLP-1s, mimic a hormone released by the gut after eating. This hormone helps regulate blood sugar, slows stomach emptying, and signals to the brain that you are full. While effective, these medications often cause gastrointestinal issues like nausea, stomach pain, and diarrhea.
Long and his team studied pythons because their organs can expand by 50% or more after a meal. Their energy use can also increase by over 40 times. After digestion, these changes return to normal fasting levels. Skip Maas, a molecular biologist at the University of Colorado Boulder and co-author, compared this metabolic boost to a racehorse sprinting for six days straight.
The researchers examined blood from young Burmese and ball pythons. The snakes had fasted for 28 days before eating a meal about a quarter of their body weight. Comparing blood samples before and after eating, they found 208 metabolites that increased significantly. One molecule, para-tyramine-O-sulfate (pTOS), increased more than 1,000 times its pre-meal level. pTOS is also found in human blood and rises after eating.
A New Approach to Weight Loss
The scientists then gave pTOS to obese and lean lab mice. Long stated that the molecule regulated the appetite and feeding behaviors of the mice. It did not cause the organ expansion or energy increase seen in pythons.
Obese mice given pTOS ate much less than those not given the molecule. After 28 days, they lost 9% of their body weight compared to the control group. Further tests showed pTOS targets the hypothalamus, a brain area linked to hunger. This is different from GLP-1s, which partly act on the stomach.
Leslie Leinwand, a biologist at the University of Colorado Boulder and study co-author, noted that they found an appetite suppressant that works in mice without the typical side effects of GLP-1 drugs.
More research is needed before these findings can lead to new drugs. However, this is not the first time nature has inspired weight-loss therapies. GLP-1 drugs, originally for type 2 diabetes, were inspired by reptiles. Gila monster venom contains a protein called exendin-4, which mimics human GLP-1 and lasts a long time in the body. A synthetic version of exendin-4 became the first GLP-1 drug approved in 2005.
Deep Dive & References: Appetite-suppressing molecule in python blood - Nature Metabolism, 2026
