Researchers uncover how distinct brain regions mediate the effects of GIPR agonists and antagonists on appetite and weight loss, paving the way for more personalised obesity therapies.
Researchers have identified two separate brain circuits that help explain why both stimulating and blocking the glucose-dependent insulinotropic polypeptide receptor, or GIPR, can drive weight loss. In a paper published in Nature Metabolism, scientists at the University of Cambridge reported that GIPR agonism and antagonism act through different regions of the brain to suppress appetite and affect body weight.
The team used mice with GIPR removed from either the area postrema, a hindbrain region involved in nausea and feeding control, or the hypothalamus, a key appetite-regulating centre. According to the study, animals lacking GIPR in the area postrema no longer responded normally to the appetite-suppressing effects of acyl-GIP, a GIPR agonist. By contrast, mice without hypothalamic GIPR still responded to acyl-GIP, but lost the extra weight-loss benefit that came from pairing a GIPR antagonist with the GLP-1 receptor agonist liraglutide.
The findings help clarify a long-running paradox in obesity research. Earlier work had already shown that both GIPR agonists and antagonists can enhance weight loss when combined with GLP-1-based therapies, despite appearing to pull in opposite directions. A related Nature Metabolism study from 2025 found that GIPR agonism and antagonism lowered body weight through different mechanisms in male mice, while a Nature Reviews Endocrinology commentary published in August 2026 said the new work shows the two strategies rely on distinct brain regions.
The Cambridge group also found that the hypothalamic GIPR pathway was important for the extra effect seen when GIPR antagonism was combined with liraglutide or the amylin receptor agonist cagrilintide. That suggests the brain’s response to GIP signalling is more compartmentalised than previously thought, and that future obesity drugs may need to target different neural circuits depending on whether the goal is to reduce appetite directly or to amplify the effect of other metabolic therapies.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
