Ghrelin is far more than a hunger hormone—it regulates immunity, brain health, cardiovascular function, and bone | Research

The takeaway

Modern research reveals ghrelin as a pleiotropic peptide regulating feeding, growth hormone, glucose homeostasis, cardiovascular tone, bone remodeling, immunity, neuroprotection, and even addiction, making the ghrelin-GHSR1a axis a major drug target.

Beyond hunger
Ghrelin regulates at least 8 major physiological systems through GHSR1a signaling, with emerging roles in neuroprotection and addiction

What the researchers found

Ghrelin acts as a pleiotropic regulator across feeding, GH release, glucose homeostasis, cardiovascular tone, bone remodeling, immunity, neuroprotection, and addiction. Cryo-EM structures reveal bipartite GHSR1a binding pocket enabling biased signaling. Des-acyl ghrelin and mini-ghrelins have distinct, context-dependent effects. LEAP-2 and GOAT inhibitors are emerging therapeutic strategies.

Why it matters

Understanding ghrelin's full scope of activity—far beyond hunger—opens multiple therapeutic avenues. The ghrelin system could be targeted for obesity, inflammatory diseases, neuropsychiatric conditions, and addiction, representing a major druggable axis in the post-GLP-1 era.

The numbers in context

No specific clinical trial data; reviews structural and functional data from preclinical and clinical literature.

How the study worked

Comprehensive narrative review synthesizing structural biology, signaling, physiology, and therapeutic development of the ghrelin system.

Who was studied

N/A

What this study cannot tell us

Narrative review without systematic methodology. Many emerging applications are based on preclinical data. Clinical translation of ghrelin-based therapeutics has been slow despite strong preclinical rationale.

How to read the evidence

Comprehensive narrative review synthesizing structural, preclinical, and clinical evidence. Strong mechanistic foundation but many applications remain preclinical.

When this study was published

Published in 2025; incorporates latest cryo-EM structural data and emerging therapeutic approaches.

The bigger picture

As GLP-1 drugs dominate metabolic medicine, ghrelin and its regulatory system (including LEAP-2 and GOAT) represent the next frontier. Structural insights into biased signaling at GHSR1a could enable precision therapeutics that activate beneficial pathways while avoiding unwanted effects.

Questions still open

Can biased GHSR1a agonists achieve therapeutic selectivity for specific ghrelin pathways?
Will LEAP-2-based strategies prove effective for appetite control in clinical trials?
How does ghrelin system modulation interact with GLP-1 agonist therapy?

Common questions

What does ghrelin do besides making you hungry?

Ghrelin regulates far more than appetite: it influences growth hormone release, blood sugar control, heart function, bone health, immune responses, brain protection, stress responses, and even addiction. It's now considered one of the most versatile hormones in the body.

Could ghrelin-based drugs treat diseases beyond obesity?

Potentially yes. Research suggests targeting the ghrelin receptor (GHSR1a) could help with inflammatory diseases, Alzheimer's disease, depression, addiction, and bone disorders. New structural insights are enabling the design of drugs that activate specific beneficial pathways without unwanted side effects.

Read the original research

Beyond Hunger: The Structure, Signaling, and Systemic Roles of Ghrelin.

International journal of molecular sciences, 26(22)

View on PubMed ↗Publisher’s paper ↗

Citation

Polishchuk, Hlafira; Guzik, Krzysztof; Kantyka, Tomasz. (2025). Beyond Hunger: The Structure, Signaling, and Systemic Roles of Ghrelin.. International journal of molecular sciences, 26(22). https://doi.org/10.3390/ijms262210996