Growth Factors Peptides
Peptides that influence growth hormone secretion and cellular growth processes
About This Category
Growth factor peptides operate through the hypothalamic-pituitary axis to regulate endogenous growth hormone (GH) secretion and downstream IGF-1 signaling. This category encompasses two distinct mechanistic classes: growth hormone-releasing hormone (GHRH) analogs, which bind pituitary GHRH receptors to stimulate GH pulse amplitude, and growth hormone secretagogues (GHS), which activate ghrelin receptors (GHSR-1a) to trigger GH release through a complementary pathway.
GHRH analogs such as Sermorelin and CJC-1295 mimic the action of endogenous GHRH, with CJC-1295 incorporating a Drug Affinity Complex (DAC) modification that extends its half-life to several days. GHS peptides including Ipamorelin, GHRP-2, GHRP-6, and Hexarelin stimulate GH secretion via ghrelin receptor activation, with varying degrees of selectivity and secondary hormonal effects. IGF-1 LR3 operates downstream of this axis, binding directly to IGF-1 receptors with an extended half-life compared to endogenous IGF-1. Follistatin-344 takes a distinct approach, neutralizing myostatin to remove a key brake on muscle protein synthesis.
Research across this category consistently focuses on body composition, metabolic effects of GH restoration, and the differential pharmacokinetics of pulsatile versus sustained GH stimulation. The selectivity profile of each peptide - particularly regarding cortisol, prolactin, and appetite stimulation - is a key differentiator studied in preclinical and early clinical research.
Key Mechanisms
- GHRH receptor (GHRHR) agonism
- Ghrelin receptor (GHSR-1a) agonism
- IGF-1 receptor (IGF-1R) signaling
- Myostatin neutralization via follistatin binding
- Pulsatile GH secretion modulation
- GH/IGF-1 axis downstream signaling
Peptides in Growth Factors
Ipamorelin
Ipamorelin is a selective growth hormone secretagogue and ghrelin receptor agonist. It stimulates the release of growth hormone from the pituitary gland without significantly affecting cortisol or prolactin levels.
CJC-1295
CJC-1295 is a synthetic analog of growth hormone releasing hormone (GHRH) with a Drug Affinity Complex that extends its half-life significantly compared to native GHRH.
GHRP-6
GHRP-6 is a synthetic hexapeptide that stimulates growth hormone release through the ghrelin receptor. It was one of the first growth hormone releasing peptides developed.
GHRP-2
GHRP-2 is a synthetic growth hormone secretagogue that stimulates GH release through the ghrelin receptor. It is considered one of the most potent GHRPs for GH stimulation.
Hexarelin
Hexarelin is a synthetic growth hormone secretagogue and one of the most potent GHRPs. It has been studied for cardioprotective effects in addition to GH release properties.
Sermorelin
Sermorelin is a synthetic analog of growth hormone releasing hormone (GHRH) containing the first 29 amino acids, which represent the active portion of the natural hormone.
Follistatin 344
Follistatin 344 is a naturally occurring glycoprotein that functions as a potent inhibitor of myostatin, activin, and other members of the TGF-beta superfamily. It has been extensively studied for its role in promoting skeletal muscle growth and as a gene therapy candidate for muscular dystrophy.
IGF-1 LR3
IGF-1 LR3 is a modified form of insulin-like growth factor-1 with an arginine substitution at position 3 and a 13-amino acid N-terminal extension, designed to have reduced binding to IGF-binding proteins and an extended biological half-life.