Ghrelin Hormone: A Systematic Review of Its Effects on Alzheimer's and Parkinson's Disease | Research

The takeaway

Systematic review of ghrelin's effects on Alzheimer's and Parkinson's finds consistent neuroprotective evidence, with ghrelin reducing neuroinflammation, oxidative stress, and protein aggregation in both conditions.

Dual protection
Ghrelin showed neuroprotective effects in both Alzheimer's (reduced amyloid) and Parkinson's (reduced synuclein) across multiple studies

What the researchers found

Ghrelin consistently showed neuroprotective effects in AD and PD studies: reduced neuroinflammation, oxidative stress, and pathological protein aggregation, with improved cognitive and motor outcomes.

Why it matters

Neurodegenerative diseases have limited treatments. Ghrelin is a natural peptide with multi-target neuroprotective effects that could be developed into a new therapeutic approach for AD and PD.

The numbers in context

The review distinguishes between acylated ghrelin (AG), which activates brain receptors, and unacylated ghrelin (UAG), which does not have these brain effects.

How the study worked

Systematic review of published studies on ghrelin's effects in Alzheimer's and Parkinson's disease, covering preclinical and clinical evidence.

Who was studied

N/A — systematic review of preclinical and clinical ghrelin research

What this study cannot tell us

Most evidence is preclinical. Clinical data is limited. Ghrelin has effects on appetite and growth hormone that may cause unwanted side effects. Optimal dosing for neuroprotection is unknown.

How to read the evidence

Moderate evidence: systematic review with consistent findings across studies, though most evidence is preclinical.

When this study was published

Published in 2025. Most comprehensive review of ghrelin in neurodegeneration to date.

The bigger picture

The metabolic peptide-neurodegeneration connection is increasingly recognized. Ghrelin, GLP-1, and insulin signaling all appear to protect the brain. Understanding which metabolic peptides offer the strongest neuroprotection could lead to new strategies for preventing and treating Alzheimer's and Parkinson's.

Questions still open

Could ghrelin receptor agonists be developed specifically for neuroprotection?
Would combining ghrelin agonists with GLP-1 drugs provide synergistic brain protection?
Does ghrelin deficiency contribute to neurodegenerative disease risk?

Common questions

Can the hunger hormone protect the brain?

Yes — ghrelin does much more than stimulate appetite. This review shows it reduces brain inflammation, combats oxidative damage, and prevents the protein clumping that drives both Alzheimer's and Parkinson's. These neuroprotective effects make ghrelin a promising target for brain disease treatment.

Could a ghrelin drug treat Alzheimer's?

The preclinical evidence is encouraging — ghrelin reduces amyloid-beta and improves cognition in Alzheimer's models. However, clinical trials in humans are needed, and managing ghrelin's appetite-stimulating effects alongside neuroprotection is a challenge.

Read the original research

Effects of Ghrelin Hormone on Alzheimer's and Parkinson's Disease: A Systematic Review of the Existing Literature.

ACS chemical neuroscience, 16(21), 4159-4171

View on PubMed ↗Publisher’s paper ↗

Citation

Abdulazeez, Yousif; Utami, Rifka Nurul; Al-Jamal, Khuloud T; Mok, Zi Hong. (2025). Effects of Ghrelin Hormone on Alzheimer's and Parkinson's Disease: A Systematic Review of the Existing Literature.. ACS chemical neuroscience, 16(21), 4159-4171. https://doi.org/10.1021/acschemneuro.5c00683