Summary: A rare intracranial recording study shows that tirzepatide, a combined GLP-1 and GIP receptor agonist, can transiently suppress craving-related neural activity in a central reward circuit of the human brain. Implanted electrodes in a patient with treatment-resistant obesity and longstanding loss of control eating captured a shutdown of signaling in the nucleus accumbens shortly after drug exposure, followed by a return of that activity months later.
These direct brain recordings provide a unique, real-time view of how incretin-based therapies engage mesolimbic reward circuitry. The findings suggest potential short-term benefits for reducing food preoccupation and binge impulses, but they also highlight that current formulations may not provide durable control of impulsive eating behaviors.
Key Facts:
- Temporary neural suppression: In this single case, tirzepatide briefly reduced craving-associated activity in the nucleus accumbens before the signals and symptoms re-emerged.
- Direct human brain data: Implanted intracranial electrodes allowed researchers to observe how GLP-1/GIP drugs alter reward circuitry in real time.
- Not optimized for impulse control: While promising for short-term reduction of food preoccupation, current GLP-1/GIP therapies may not provide long-term relief for binge-related impulsivity.
Source: University of Pennsylvania
Overview: Researchers at the Perelman School of Medicine, University of Pennsylvania, report a rare first-in-human observation of how tirzepatide affects electrical activity in the nucleus accumbens (NAc), a core hub of the brain’s reward and motivation system. The patient, who had severe, treatment-resistant obesity and persistent food preoccupation, showed a clear suppression of NAc signaling on tirzepatide that coincided with the disappearance of craving thoughts. This suppression, however, lasted only a few months before neural patterns and food preoccupation reappeared.
Tirzepatide is an incretin-based medication that activates both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors. Originally developed to manage blood glucose in type 2 diabetes and now used for weight reduction, these drugs are being evaluated for broader effects on disorders linked to impulsivity, including binge eating disorder (BED). Until now, however, how they change human reward-circuit dynamics in real time had not been demonstrated directly inside the human brain.
“This study offers major insights into how these drugs act within the brain and will guide efforts to explore new clinical uses,” said Casey H. Halpern, MD, professor of Neurosurgery and head of the Division of Stereotactic and Functional Neurosurgery. At the same time, Halpern cautioned that it is premature to call GLP-1/GIP agents miracle cures for impulse-control conditions beyond their approved uses.
A common and debilitating condition
Loss of control eating and severe food preoccupation affect millions of people with obesity and are central features of eating disorders such as binge eating disorder, which is one of the most common eating disorders in the United States. People who experience these problems report intrusive, repetitive thoughts about food—often termed “food noise”—and they may continue to eat past satiety or binge despite wanting to stop.
Eating behaviors are governed by interacting brain systems: homeostatic circuits in the hypothalamus and hedonic circuits in the mesolimbic pathway, including the nucleus accumbens. In many individuals with obesity and BED, NAc signaling and its network dynamics are dysregulated, producing abnormal motivation and impulsivity toward food. Even without a formal BED diagnosis, up to 60 percent of people with obesity report persistent food preoccupation that contributes to distress and disordered eating.
These behaviors also carry significant emotional consequences. Studies have linked binge eating and related impulsivity with higher rates of mood dysregulation and suicide risk, underscoring the need for more effective, targeted treatments.
A new approach to managing food preoccupation
The report describes a 60-year-old woman identified as “Participant 3” who struggled with severe, treatment-resistant obesity and persistent obsessive thoughts about food. She described frequent snacking, ordering takeout, and eating until uncomfortably full, with strong cravings for both sweet and salty processed foods. Prior therapy attempts included behavioral treatments, bariatric surgery, and multiple medications; a GLP-1 agent (dulaglutide) had not reduced her weight or food preoccupation.
When standard treatments failed, she enrolled in a clinical trial led by Halpern that involves implanting intracranial electrodes in the NAc. The trial’s aim is to detect and stop craving-related neural signals with high-frequency electrical stimulation, a personalized approach modeled on devices used for epilepsy and Parkinson’s disease. Before stimulation began, researchers recorded baseline NAc activity as participants encountered binge-triggering foods.
The brain–binge connection
Previous work from the Halpern lab identified a distinctive electrophysiological signature in the NAc—an increase in low-frequency (delta–theta) power—that precedes episodes of food preoccupation and the urge to binge. In a pilot study, delivering stimulation when this signature appeared reduced bingeing behavior.
In the current trial, intracranial electroencephalography (iEEG) electrodes record NAc activity continuously, allowing the team to correlate neural events with subjective cravings and eating behavior. This provides an opportunity to examine how pharmacologic therapies alter those neural markers.
A unique chance to observe tirzepatide’s brain effects
Because Participant 3’s doctor prescribed tirzepatide to manage her type 2 diabetes in the perioperative period, researchers had a rare opportunity to study the drug’s effect on NAc signals before stimulation was ever delivered. Her tirzepatide dose was gradually increased to the therapeutic range prior to and after electrode implantation, enabling continuous monitoring of drug-related changes in neural activity and subjective food preoccupation.
Short-term suppression, long-term questions
After reaching the full tirzepatide dose, Participant 3 reported a disappearance of food preoccupation, and recordings showed a marked quieting of the NAc activity normally associated with cravings. This aligned with the idea that the drug modulated aberrant mesolimbic activity linked to impulsive eating. However, after approximately five months the craving-associated NAc signals reappeared, and the participant again experienced intense food preoccupation. In contrast, trial participants who were not taking tirzepatide displayed persistent elevated NAc activity and frequent craving episodes, consistent with prior findings.
Investigators emphasize that while incretin-based agents like tirzepatide are highly effective for glucose control and weight loss, their effects on dysregulated eating and impulsivity appear to be incomplete and time-limited in this case. The observations support further research to define whether different dosing strategies, adjunctive therapies, or novel compounds could produce more durable improvements in impulsive eating behaviors.
“These recordings from inside the human brain provide compelling evidence that GLP-1/GIP drugs can modulate the neural circuits that drive food preoccupation,” said co-first author Wonkyung Choi. “The challenge now is to translate these insights into treatments tailored to the impulsivity components of obesity and related eating disorders.”
Funding: This research was supported by grants from the National Institutes of Health (7UH3NS103446-03, 1R01MH124760-01A1, R25MH119043 and T32NS091008).
Key Questions Answered:
A: In this case, tirzepatide temporarily suppressed craving-related activity in the nucleus accumbens, the reward center associated with food preoccupation and loss-of-control eating.
A: No. In this participant, the neural signature and subjective food preoccupation returned after several months, indicating a transient effect.
A: These drugs may reduce food preoccupation in the short term, but they are not yet optimized for durable control of food-related impulsivity. Further research is needed to develop targeted, long-lasting treatments.
Editorial Notes
– This article summarizes findings reviewed from the journal publication and includes contextual notes from the reporting team.
About this research
Author: Kelsey Geesler
Source: University of Pennsylvania
Contact: Kelsey Geesler – University of Pennsylvania
Image credit: Neuroscience News
Original Research: “Brain activity associated with breakthrough food preoccupation in an individual on tirzepatide” by Casey H. Halpern et al., published in Nature Medicine (open access).
Abstract
Brain activity associated with breakthrough food preoccupation in an individual on tirzepatide
Obesity and related disorders often involve intrusive food preoccupation that can lead to dysregulated eating. While incretin-based therapies reduce weight, their effects on pathological food preoccupation are poorly understood. Direct recordings from the human nucleus accumbens reveal that short-term tirzepatide exposure initially suppressed craving-associated neural activity, but that episodes of severe food preoccupation later recurred and were preceded by increased delta–theta (≤7 Hz) power in the NAc. These observations suggest that modulation of mesolimbic circuitry by incretin-based drugs may underlie changes in food preoccupation, but also indicate the need to develop approaches that produce longer-lasting control of impulsive eating behaviors.