Stanford scientists say they have zeroed in on a tiny natural peptide that, at least in the lab, behaves a lot like Ozempic without many of the gut troubles that come with the drug. The 12-amino-acid fragment, dubbed BRP, cut food intake by as much as 50% after a single injection in mice and minipigs and drove mostly fat-specific weight loss in obese mice given the peptide over two weeks.
How the team found BRP
The work is detailed in a peer-reviewed paper in Nature, published March 5, 2025. The researchers used an AI-guided search to hunt for previously uncharacterized peptide fragments, running a program called Peptide Predictor on more than 2,600 candidates. They also posted the predictor’s code on GitHub, so other labs can replicate and extend the screen.
What the animal tests showed
In controlled experiments, a single injection of BRP given before a meal cut short-term food intake by up to 50% in both lean mice and minipigs. Obese mice treated once a day for 14 days lost about 3 grams, almost entirely from fat, while untreated mice in the same setup gained roughly the same amount of weight. Treated animals also showed better glucose and insulin tolerance, and behavior tests did not pick up any increase in nausea-like responses or shifts in movement, water intake or fecal output, according to Stanford Medicine.
How BRP works differently than GLP-1 drugs
Mechanistic experiments in the study found that BRP switches on neurons in the hypothalamus and activates a CREB–FOS signaling cascade while operating independently of the GLP-1 receptor, leptin and MC4R. That profile could help explain why animals did not show the gastrointestinal side effects that are familiar with GLP-1 drugs. These central effects indicate that BRP is not a GLP-1 agonist like semaglutide but instead acts as a distinct appetite-suppressing signal that targets the brain’s hunger circuitry, according to the Nature paper.
Why researchers and patients are watching
GLP-1 drugs such as Ozempic and Wegovy have delivered major weight-loss benefits but also come with a notable side-effect burden for people taking them in everyday life. A 2025 RAND survey found that roughly half of GLP-1 users reported nausea and about one-third reported diarrhea. That kind of real-world discomfort is a big reason clinicians and patients are paying attention to any candidate that might separate appetite control from gut irritation.
Patents and commercial plans
The study authors report that lead researchers on the project are named as inventors on patents covering BRP peptides, and that senior author Katrin Svensson is a co-founder of Merrifield Therapeutics, the startup expected to advance BRP toward human trials, according to Stanford Medicine. The team’s stated next steps include finding the cell-surface receptor that BRP binds to and modifying the peptide so its effects last longer, which would make dosing more convenient if it reaches the clinic.
For now, BRP remains an early-stage lab finding, not a ready-made treatment. The promising animal data, the commercial backing and the public release of the AI screening code provide an intriguing proof of concept, but the real tests lie in human safety and efficacy studies. Those trials, if they move ahead, are expected to take years. Until then, approved GLP-1 medications and guidance from health care professionals remain the established tools for managing weight and metabolic disease.
