Ghrelin's role as an orexigenic (appetite-stimulating) gut signal is coordinated with leptin, insulin, and central neuropeptides to regulate food intake as part of an integrated energy homeostasis network.
Only hunger hormoneGhrelin is the only known circulating hormone that stimulates appetite — all other known hormones suppress it
What the researchers found
Ghrelin is the only known circulating orexigenic hormone, with meal-related fluctuations and interactions with leptin, insulin, and hypothalamic neuropeptides integrating peripheral and central appetite regulation.
Why it matters
Understanding ghrelin's position in the appetite regulation network enables more strategic drug development — targeting ghrelin may be most effective when combined with other appetite pathway modulation.
How the study worked
Review of ghrelin's orexigenic signaling, meal-related dynamics, interactions with other appetite hormones, and central nervous system integration pathways.
What this study cannot tell us
Review from 2002 when ghrelin's full integration with the appetite network was still being mapped. Some proposed interactions were preliminary.
How to read the evidence
Moderate evidence from a review integrating ghrelin's orexigenic biology with the broader appetite regulation framework.
When this study was published
Published in 2002. Ghrelin's unique role as the circulating hunger hormone has been extensively confirmed.
The bigger picture
Appetite regulation is a network, not a single pathway. Ghrelin provides the hunger drive that the brain integrates with satiety signals, fat status, and energy reserves to determine eating behavior.
Questions still open
- Is ghrelin the best appetite target for obesity treatment?
- Could ghrelin analogs treat cachexia more effectively than nutritional support?
- Does ghrelin resistance develop in chronic overeaters?
Common questions
Is ghrelin the only hunger hormone?
Can blocking ghrelin help with weight loss?
Read the original research
Ghrelin, an orexigenic signaling molecule from the gastrointestinal tract.
Current opinion in pharmacology, 2(6), 665-8
Citation
Kojima, Masayasu; Kangawa, Kenji. (2002). Ghrelin, an orexigenic signaling molecule from the gastrointestinal tract.. Current opinion in pharmacology, 2(6), 665-8.