Scientists have discovered a unique chemical compound in the blood of pythons—large snakes capable of consuming enormous amounts of food and then going for long periods without eating—that sharply reduces appetite. The results of the study, conducted by researchers from the University of Colorado Boulder in collaboration with colleagues from other universities, were published in the journal Nature Metabolism.

The study shows that components in these reptiles’ blood help them remain metabolically healthy even after long fasting periods—and this discovery could serve as a starting point for new therapies against obesity and excess weight.

The compound, named pTOS by the researchers, is produced in pythons’ bodies after large meals and, as laboratory tests on mice showed, effectively suppresses hunger.

Mice given pTOS ate less over several weeks and lost weight—in one experiment, the mice lost about 9% of their body weight over 28 days. The main difference between this molecule and existing weight-loss drugs lies in the mechanism: many popular medications, such as those based on GLP-1 (like Wegovy and others), work by slowing stomach emptying and often cause side effects such as nausea. pTOS, according to preliminary data, acts directly on the brain’s appetite center without significant unpleasant effects and without noticeable muscle loss.

Researchers emphasize that this natural compound will not become a medicine overnight: much more research is needed, including clinical trials in humans, to determine its safety, efficacy, and proper dosing.

However, the fact that similar molecules are already found in humans in very small amounts—and increase after meals—offers optimism for its potential use. This could eventually lead to a new class of drugs that are safer and better tolerated than many existing treatments.

The idea of using natural mechanisms from the animal world to develop medicines is not new: for example, GLP-1–like compounds from the venom of gila monsters previously became the basis for modern anti-obesity drugs. This new discovery could be the next step in expanding the arsenal of treatments for obesity—a disease affecting millions worldwide and remaining one of the most challenging to treat.