Ghrelin and Growth-Hormone Secretagogues
What ghrelin is, how it triggers growth hormone release and appetite, and what the term growth hormone secretagogue means, kept separate from any product claims.
Content last updated . This page has not been medically reviewed.
Quick answer
Ghrelin is a hormone made mainly in the stomach. It stimulates appetite and is also an important signal that prompts the pituitary to release growth hormone (GH). A "growth hormone secretagogue" is any substance that prompts GH release; ghrelin is the body's own example. This page is about the natural hormone and its receptor, not about products sold or discussed online. For those, see growth-hormone-releasing peptides and how to evaluate peptide claims.
Evidence labels: established, mixed, preclinical (cells/animals only), insufficient evidence.
Identity and naming
| Term | Meaning |
|---|---|
| Ghrelin | Endogenous hormone, originating primarily in the stomach [1] |
| GHS receptor (GHS-R1a) | The receptor ghrelin acts on to stimulate GH release [2][3] |
| Growth hormone secretagogue | A signal or substance that prompts GH release; ghrelin is an important one [1] |
| Marketed "GH secretagogue" products | Separate topic; a name or category does not establish that a product contains the same molecule as the studied one |
What ghrelin does
- Appetite. Ghrelin stimulates appetite and food intake by binding receptors and activating hunger-promoting neurons in the arcuate nucleus. [4]
- Stomach. It accelerates gastric emptying, unlike most other gut hormones. [5]
- Growth hormone. It acts through the GHS receptor, including on GHRH neurons, and can also stimulate GH independently of GHRH and work together with it. [3]
- Pleiotropic. Ghrelin has many actions beyond GH. [2]
Ghrelin and growth
Variants of the GHS receptor gene have been linked with human height, both in healthy people and in people with growth disorders such as constitutional delay in growth and puberty, idiopathic short stature and isolated GH deficiency. [2] This is genetic association and does not show that raising ghrelin or GH would change height or health.Brain and mood
Ghrelin, GH and IGF-1 receptors are present in many brain regions, and altered signaling has been proposed as a risk factor for neurodegenerative and neuropsychiatric conditions, mostly as association. [1] Label: insufficient evidence for treatment benefit.What is not established
- Whether stimulating the ghrelin receptor produces health benefits in healthy people. We did not find that in the reviews read here.
- Higher GH or IGF-1 after a stimulus is a biomarker change, not a proven benefit. See growth hormone and IGF-1 signaling.
- In people with excess weight, ghrelin and leptin signaling may be dysregulated, which complicates simple "boost the hormone" ideas. [4]
Frequently asked questions
What is ghrelin?
A hormone originating primarily in the stomach that is also an important GH secretagogue. [1]
Is ghrelin the "hunger hormone"?
It stimulates appetite and food intake, and works against leptin. [4]
Does ghrelin speed up the stomach?
Yes. Ghrelin and motilin accelerate gastric emptying, while most other gut hormones delay it. [5]
Does ghrelin only affect growth hormone?
No. Its effect on GH is one of many actions. [2]
Is any ghrelin-mimicking product proven to help?
Not from the sources in this group. Check the specific compound on its own page.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety note
Hormone biology is not a guide to products. Unapproved compounds sold online may differ from studied molecules; see peptide safety and adverse events. Discuss any health concern with a clinician.
References
- Growth Hormone and IGF-1 Actions in the Brain and Neuropsychiatric Diseases. Physiology 2026. Read 2026-10-22.
- Ghrelin and Growth. Endocrine Development 2017. Read 2026-10-22.
- Hypothalamic GHRH. Reviews in Endocrine and Metabolic Disorders 2025. Read 2026-10-22.
- The role of leptin and ghrelin in the regulation of appetite in obesity. Peptides 2025. Read 2026-10-22.
- Gastrointestinal hormones and regulation of gastric emptying. Current Opinion in Endocrinology, Diabetes and Obesity 2019. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.