Growth ⏱ Half-life: ~30 minutes Clinical (unspecified)

Ghrelin

Ghrelin (Growth Hormone Releasing Peptide / Hunger Hormone)

Updated March 30, 2026

Evidence at a Glance

Regulatory statusClinical (unspecified)
Endogenous hormone; not an approved drug. Its long-acting analog anamorelin is approved only in Japan for cancer cachexia.
Human evidenceModerate
Animal evidenceExtensive

Ghrelin is a well-characterized endogenous appetite/GH hormone infused in many human physiology studies, but it is not an approved therapeutic on its own.

What the research does not support

  • Injected ghrelin does not build muscle or durably raise growth hormone; its GH effect is brief and it strongly stimulates hunger.
  • It is not an approved medicine anywhere; only the synthetic analog anamorelin is approved (Japan, for cancer cachexia).
  • It is not a fat-loss agent — physiologically it increases appetite and promotes fat storage and weight gain.
Half-Life
~30 minutes
Purity
≥95%
Mol. Weight
3,370.9 Da
Form
Lyophilized powder

What is Ghrelin?

Ghrelin, discovered in 1999, is a 28-amino acid peptide that requires a unique octanoyl modification on Ser3 for biological activity. It is the endogenous ligand for the receptor that synthetic growth hormone secretagogues (like GHRP-6 and MK-677) were designed to target. Understanding ghrelin physiology is essential context for anyone researching the GHRP/GHS class of peptides.

Dosage Information (Research Use)

Research: 1-5 mcg/kg IV infusion in human studies. Subcutaneous dosing studied at higher doses for cachexia. Research compound.

Reconstitution & Handling

Reconstitute in sterile saline. The active (acylated) form is less stable than des-acyl ghrelin.

Half-Life & Pharmacokinetics

~30 minutes

Reported Observations in Literature

Increased appetite (primary effect), GH elevation, potential blood glucose increase, transient flushing, mild GI stimulation. Generally well tolerated in clinical studies.

Key Research References

  • Kojima M et al. “Ghrelin is a growth-hormone-releasing acylated peptide from stomach.” Nature. 1999;402:656-60
  • Wren AM et al. “Ghrelin enhances appetite and increases food intake in humans.” J Clin Endocrinol Metab. 2001;86:5992-5

How Ghrelin Works

Ghrelin is the only known circulating orexigenic (appetite-stimulating) hormone. Produced primarily by gastric oxyntic cells, it activates the growth hormone secretagogue receptor (GHS-R1a) — the same receptor targeted by synthetic GHRPs like GHRP-6 and MK-677. Ghrelin levels rise before meals and fall after eating. Beyond appetite, ghrelin stimulates GH release from the pituitary, promotes gastric motility, and has neuroprotective and cardioprotective properties.

Research Applications

🔬 Appetite regulation and obesity
🔬 Cachexia and wasting syndromes
🔬 GH secretion physiology

Research Findings

Ghrelin administration increases food intake by 28% in human studies. Ghrelin levels are paradoxically low in obesity (except Prader-Willi syndrome). Synthetic ghrelin analogs (anamorelin) are approved in Japan for cancer cachexia. Ghrelin-O-acyltransferase (GOAT) inhibitors are under development as anti-obesity agents.

Dosage & Administration

Research: 1-5 mcg/kg IV infusion in human studies. Subcutaneous dosing studied at higher doses for cachexia. Research compound.

Safety & Side Effects

Increased appetite (primary effect), GH elevation, potential blood glucose increase, transient flushing, mild GI stimulation. Generally well tolerated in clinical studies.

Important: All safety information is derived from published research, primarily animal studies. No controlled human clinical trial data exists unless explicitly noted. This compound is sold for research purposes only.

Quick Facts

Molecular Weight 3,370.9 Da
Half-Life ~30 minutes
Purity ≥95%
Form Lyophilized powder
Storage Lyophilized: -20°C. Acylated form degrades faster than des-acyl.

Key Research References

  • Kojima M et al. "Ghrelin is a growth-hormone-releasing acylated peptide from stomach." Nature. 1999;402:656-60
  • Wren AM et al. "Ghrelin enhances appetite and increases food intake in humans." J Clin Endocrinol Metab. 2001;86:5992-5

Related Peptides

View all →
AOD-9604
Growth
Modified fragment of human growth hormone (hGH 176-191) researched specifically for fat metabolism without GH-related side effects.
View Profile → Buy Now
ACE-031
Growth
Myostatin pathway decoy receptor researched for increasing lean mass in muscle-wasting conditions.
View Profile →
IGF-1 LR3
Growth
Long-acting IGF-1 analog with extended half-life for sustained anabolic signaling in muscle and tissue research.
View Profile → Buy Now