Researchers at Stanford Medicine have uncovered a small, naturally occurring peptide that could become a new weight-loss option with fewer gastrointestinal side effects than current GLP-1 drugs such as Ozempic, Wegovy and Mounjaro. The 12–amino-acid molecule, called BRP, appears to reduce appetite by acting chiefly in the hypothalamus—the brain’s primary hunger regulator—rather than strongly stimulating the hindbrain, which is linked to sensations of visceral fullness and the nausea often reported with GLP-1–based therapies.
Current injectable GLP-1 mimetics mimic a gut hormone to suppress appetite and produce substantial, surgery-like weight loss for many people, but they can also cause nausea, vomiting, diarrhea, abdominal pain and constipation. Because circulating hormones typically reach only two brain regions across the blood–brain barrier—the hypothalamus and the hindbrain—researchers believe the different site of BRP’s action may explain a potentially milder side-effect profile.
In preclinical studies, obese mice given daily BRP injections lost weight while untreated controls gained weight. The compound seemed to preferentially reduce fat while preserving muscle mass, an advantage that could matter for long-term metabolic health. Stanford investigators discovered BRP using an AI system they built, called Peptide Predictor, which scanned roughly 20,000 human genes to generate about 2,683 candidate hormone-like peptides. The team narrowed those to about 100 for laboratory testing, with BRP emerging as a promising lead.
Experts praise the scale of the search and the approach but urge caution. Success in rodent models does not ensure safety or effectiveness in humans, and obesity requires long-term treatment, so any new therapy must show a strong safety profile over time. GLP-1 drugs are adapted from a natural hormone and have been chemically modified to last longer in the body; BRP could potentially be optimized in similar ways to improve durability.
Katrin Svensson, the study’s senior author, has co-founded a company to pursue human trials. Even if BRP reaches the clinic, GLP-1–based medicines are likely to remain important because they offer benefits beyond weight loss, including lowered cardiovascular risk. Still, BRP could expand the available toolkit for treating obesity and offer an alternative for people who cannot tolerate current therapies or prefer a different mechanism. The broader hope is that more therapeutic options will help more people find a sustainable, effective treatment for long-term weight management.