Scientists have identified a naturally occurring molecule that could lead to a new generation of weight loss drugs. In early animal experiments, the molecule, called BRP, suppressed appetite and promoted fat loss much like semaglutide, the active ingredient in Ozempic, while appearing to avoid some of that drug's side effects. The study is published in Nature.
The team found BRP with the help of artificial intelligence. They built a program called Peptide Predictor that scanned the roughly 20,000 human genes that encode proteins, searching for small protein fragments, called peptides, that a specific enzyme would likely cut free and that could work as hormones, the chemical messengers that coordinate appetite and energy use. Filtering produced 373 candidate proteins, and the researchers tested 100 of the resulting peptides on nerve cells grown in the laboratory. One previously unknown peptide, just 12 amino acids long, raised neuronal activity tenfold, far more than the hormone GLP-1, which tripled it. The scientists named it BRP after its parent protein, BRINP2.
Strong appetite suppression in animals, without the usual side effects
In lean mice and minipigs, an injection of BRP before feeding cut food intake by up to 50 percent over the following hour. Obese mice treated daily for 14 days lost an average of 3 grams, nearly all of it fat rather than muscle, while untreated mice gained about 3 grams. Treated animals also showed improved glucose and insulin tolerance, meaning their bodies handled sugar more effectively. Unlike semaglutide, whose receptors sit in the brain, gut, and pancreas, BRP appears to act specifically in the hypothalamus, the brain region that controls hunger and metabolism.
The finding matters because existing drugs, while effective, often cause nausea, constipation, and muscle loss, and a treatment that targets appetite more precisely could avoid those problems. The work also shows how AI can speed up the search for useful molecules hidden among thousands of ordinary protein fragments. Still, BRP is at an early stage: it has not been tested in people, its receptor is unknown, and human trials are needed to determine whether it is truly safe and effective.