NIH-funded research published in Nature found that oral GLP-1 drugs including Orforglipron suppress pleasure-driven eating in mice by activating deep brain reward circuits and reducing dopamine signaling in the central amygdala, highlighting potential implications beyond obesity treatment.
Written By: Farha Farheen and
Fariha Sameen, PharmD
Reviewed By: Dr. Rahul Gaikwad, MBBS,
MD-General Medicine
An NIH-funded study published in Nature reveals that oral GLP-1 weight-loss drugs may suppress “pleasure-driven” eating by acting on deep brain reward circuits. The findings provide new insight into how next-generation oral GLP-1 therapies work and could eventually expand their therapeutic potential beyond obesity to conditions involving dysfunctional reward signaling, including addiction and substance use disorders.
Researchers at the University of Virginia specifically investigated small-molecule GLP-1 receptor agonists, including FDA-approved Orforglipron and investigational Danuglipron. The study showed that both drugs reduced hedonic feeding in mice by directly influencing brain reward pathways linked to pleasure and craving.
GLP-1 receptor agonists have become one of the most widely discussed classes of obesity medicines in recent years. Previous research has extensively explored injectable peptide-based GLP-1 therapies such as Semaglutide, which primarily suppress hunger-driven eating through networks in the hypothalamus and hindbrain. However, scientists have had a much less clear understanding of how oral small-molecule GLP-1 drugs function inside the brain.
“As the accessibility of these medications continues to rise and patient uptake increases, it’s crucial that we understand the neural mechanisms underlying the effects we’re seeing,” said Lorenzo Leggio, clinical director of the National Institute on Drug Abuse.
Researchers Identified Activity in the Central Amygdala
To better understand how these oral compounds work, the research team genetically modified mice to express more human-like GLP-1 receptors. The animals were then treated with orforglipron or danuglipron while scientists mapped brain regions activated by the drugs.
While the oral GLP-1s activated familiar appetite-regulating areas, researchers also observed strong activity in the central amygdala, a deep brain region associated with desire, motivation, and reward processing.
This finding suggested that small-molecule GLP-1s can reach neural territories previously thought inaccessible to this class of medicines. Researchers said this mechanism appears distinct from the pathways typically associated with injectable peptide-based GLP-1 therapies.
Further experiments showed that activation of the central amygdala reduced dopamine release into reward centers, curbing eating driven by pleasure rather than energy needs.
“We’ve known that GLP-1 drugs suppress feeding behaviour driven by energy demand. Now it seems oral small-molecule GLP-1s also dial back eating for pleasure by engaging a brain reward circuit,” said co-corresponding author Ali Guler.
Findings Could Have Implications Beyond Obesity
Researchers believe the discovery may eventually have broader implications for disorders involving abnormal reward signaling, including addiction and substance use disorders. According to the scientists, the next step is to investigate whether these oral GLP-1 therapies can also reduce cravings for substances other than food.
The study was supported by several NIH institutes, including the National Institute of Neurological Disorders and Stroke, National Institute of General Medical Sciences, National Heart, Lung, and Blood Institute, and National Cancer Institute.
Researchers emphasized that these findings were observed in mice. The study was not conducted as a clinical trial, and oral GLP-1 therapies are not FDA-approved for substance use disorders or neurological indications.
The original research was published in Nature.
Reference
A brain reward circuit inhibited by next-generation weight-loss drugs in mice | Nature
About the Writer
Farha Farheen, PharmD (LinkedIn) is a pharmacy professional with a strong interest in pharmacovigilance and clinical research. She has completed her Doctor of Pharmacy (Pharm.D) along with her internship as a Clinical Pharmacist. She has hands-on experience in adverse drug reaction (ADR) reporting, safety data documentation, and pharmacovigilance workflows, and is proficient in using VigiFlow. She is also a patent holder for an antibacterial formulation enriched with bioactive substances, granted by the German Patent and Trademark Office.
About the Writer
Fariha Sameen, PharmD (LinkedIn), is a clinical pharmacy professional with hands-on experience in patient counselling, medication review, therapeutic monitoring, and clinical documentation across multiple departments. She has experience identifying and assessing drug-related problems and supporting medication safety practices. Her interests include pharmacovigilance, ADR reporting, clinical research, and medical writing focused on clear, evidence-based communication.