Stanford researchers have identified a tiny peptide that can suppress appetite and trigger weight loss similar to semaglutide, the blockbuster drug in Ozempic, but without the nausea, constipation, and muscle loss that plague current users.
The molecule, called BRP, emerges from a fundamentally different metabolic pathway than semaglutide. In animal tests, it produced dramatic appetite suppression, cut food intake by up to 50% in a single dose, and caused obese mice to lose weight from fat rather than lean tissue.
The breakthrough hinged on artificial intelligence sifting through vast genetic datasets to uncover a biological signal that traditional methods would have buried in noise.
Katrin Svensson, an assistant professor of pathology at Stanford and senior author of the research published in Nature, explained the fundamental difference in how BRP works. "Semaglutide targets receptors throughout the body, in the brain, gut, pancreas and elsewhere," she said. "That widespread activation is why it causes so many side effects. BRP appears to act specifically in the hypothalamus, the brain region that controls appetite and metabolism."
This precision targeting could represent a meaningful advantage. Semaglutide's effects on the digestive system slow food movement and lower blood sugar, properties that drive both its benefits and its downsides. A molecule that influences only appetite control might achieve weight loss without triggering gastrointestinal misery.
The discovery process itself reveals how computational power is reshaping drug research. Researchers created an algorithm called Peptide Predictor that scanned all 20,000 human protein-coding genes for molecular signatures where specific enzymes cut proteins into peptides. From hundreds of thousands of possible fragments, the AI narrowed the field to 100 candidates worth testing in the laboratory.
One peptide stood out immediately. Made of only 12 amino acids, BRP activated neuron-like cells grown in dishes ten times more strongly than controls. For comparison, glucagon-like peptide 1, or GLP-1, the natural compound semaglutide mimics, boosted activity threefold.
When researchers injected BRP into lean mice and minipigs before feeding, animals consumed half their usual food during the next hour. Over 14 days of daily injections, obese mice shed weight almost entirely from fat stores while gaining better control of blood glucose and insulin response.
Perhaps most striking, the treated animals showed no behavioral signs of nausea or digestive distress. Fecal production remained normal, suggesting the drug does not impede digestion the way semaglutide does. Muscle loss, a concern with aggressive weight loss drugs, did not appear.
Svensson has co-founded a company planning to launch human clinical trials in the near future. But significant work remains. Researchers must identify the precise cellular receptor BRP binds to, trace the full biological cascade triggered by that binding, and solve a practical problem: small peptides break down quickly in the body, potentially limiting how long they work.
"For decades, we've lacked truly effective obesity treatments," Svensson said. "Nothing we've tested compares to semaglutide. We're eager to see if it's safe and effective in people."
The research involved collaborators from UC Berkeley, the University of Minnesota, and the University of British Columbia.
Author Jessica Williams: "If BRP delivers Ozempic-level weight loss without the bathroom disasters, it could reshape how we treat obesity, but those animal data need to survive human testing first."
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