Stanford Medicine researchers say they have identified a naturally occurring 12–amino-acid peptide, BRP, that suppressed appetite and reduced body weight in animal studies. The team used a computational tool dubbed “Peptide Predictor” to identify the molecule, and reported that BRP produced anti-obesity effects in mice and minipigs without signs of nausea- or aversion-like responses seen with some GLP-1–based drugs.
The research was published March 5, 2025, in Nature, where the authors described using a computational approach to map thousands of previously uncharacterized peptide fragments produced from human prohormones and then testing candidates for biological activity.
According to Stanford Medicine, BRP—short for BRINP2-related peptide—appeared comparable to semaglutide in suppressing appetite and reducing body weight in animal models, while avoiding some commonly reported side effects of GLP-1–based medications such as nausea and constipation in those tests.
In experiments cited by Stanford, an intramuscular injection of BRP given before feeding reduced food intake over the next hour by up to 50% in both lean mice and Yucatan minipigs. In obese mice treated with daily injections for 14 days, the animals lost an average of about 3 grams—reported to be almost entirely fat—while control animals gained about 3 grams over the same period.
Assistant professor of pathology Katrin Svensson said semaglutide’s targets are found across multiple tissues, contributing to broad physiological effects. By contrast, she said, “BRP appears to act specifically in the hypothalamus, which controls appetite and metabolism.”
The Nature paper reports that pharmacologically administered BRP reduced food intake and showed anti-obesity effects in mice and pigs “without inducing nausea or aversion,” and Stanford’s summary of behavioral and physiological testing said treated animals showed no differences in movement, anxiety-like behavior, water intake or fecal production.
Stanford Medicine also disclosed that Svensson co-founded Merrifield Therapeutics, and that she and lead author Laetitia Coassolo are inventors on patents related to BRP peptides for metabolic disorders. Stanford said the company was formed to move the molecule toward clinical testing in humans, though the published findings described animal studies rather than human trial results.
