GHRP-6Also known as: Growth Hormone Releasing Peptide-6, Hexapeptide GHRP-6

Mechanism of Action

GHRP-6 acts as an agonist at the ghrelin receptor (GHS-R1a), stimulating the pituitary gland to increase secretion of growth hormone (GH). This leads to downstream effects including elevated IGF-1 levels, enhanced muscle protein synthesis, and metabolic regulation. The peptide mimics the natural ligand ghrelin, promoting GH release and impacting appetite regulation via these receptors.

Reported Research Benefits

Used extensively in laboratory research to study GH release mechanisms, IGF-1 elevation, muscle growth and repair, fat metabolism, and appetite regulation. It is investigated for its anabolic and metabolic effects, particularly in sport science, endocrinology, and metabolic disorder models.

Dosing Protocol & Reconstitution

Typically supplied as lyophilized powder requiring reconstitution with bacteriostatic water. In research settings, administered subcutaneously often via insulin syringes. Precise dosing varies by protocol but is usually in the microgram to low milligram range per injection. Stability preserved refrigerated (2–8°C) for up to 60 days after reconstitution.

Research Notes

GHRP-6 shows robust stimulation of GH secretion but has a short half-life (~20-30 minutes). Studies demonstrate increased IGF-1 levels following administration, contributing to anabolic signaling and improved muscle recovery. Also investigated for effects on fat oxidation and appetite modulation via ghrelin pathways.

Research Summary

GHRP-6 is a hexapeptide growth hormone secretagogue that stimulates GH release via ghrelin receptor (GHSR-1a) activation. It produces significant GH pulses and is one of the most studied GHRPs in human trials. Beyond GH release, it demonstrates cardioprotective, hepatoprotective, and anti-inflammatory properties in preclinical models.

Side Effects & Safety

Notable increase in appetite (hunger) is a hallmark side effect via ghrelin receptor agonism. Water retention, cortisol and prolactin elevation, and fatigue are possible. Less selective than Ipamorelin for GH-only effects. Potential for insulin resistance with chronic elevated GH.

Stability & Storage

Refer to research notes

Molecular Data

Sequence: His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Molecular Formula: C46H56N12O6
Molecular Weight: 873 g/mol
CAS Number: 87616-84-0
IUPAC Name: N-hexapeptide with sequence: histidyl-D-tryptophyl-alanyl-tryptophyl-D-phenylalanyl-lysinamide

Primary literature: https://pubmed.ncbi.nlm.nih.gov/?term=GHRP-6+growth+hormone+releasing+peptide