GHRH analogs, ghrelin-receptor GHRPs, and the compounds that prompt the pituitary to release growth hormone — plus the hormone itself. Understand the three levers, how they are paired, and where each stands.
Start with the fundamentals before comparing compounds.
13 compounds in this research area. Each links to a full profile, dosing chart, and sourcing.
Growth-hormone-releasing hormone (GHRH) analog
A synthetic GHRH analog studied for stimulating growth-hormone release. Exists in a short-acting 'no-DAC' form (modified GRF 1-29) and a long-acting 'DAC' form.
Ghrelin-receptor agonist (GH secretagogue)
A selective ghrelin-receptor agonist studied for stimulating growth-hormone release with comparatively little effect on cortisol or prolactin, making it a frequently referenced 'clean' secretagogue.
Growth-hormone-releasing hormone (GHRH) analog
A GHRH (1-29) analog — the shortest fully active fragment of GHRH — historically used clinically as a diagnostic agent and studied for supporting endogenous growth-hormone output.
Stabilized GHRH analog
A stabilized GHRH analog that is FDA-approved (as Egrifta) to reduce excess visceral adipose tissue in HIV-associated lipodystrophy — one of the few peptides in this index with an approved human indication.
Growth-hormone-releasing peptide (ghrelin-receptor agonist)
A potent growth-hormone-releasing peptide and ghrelin-receptor agonist studied for stimulating GH release; also investigated as a diagnostic test of pituitary GH reserve.
Growth-hormone-releasing peptide (ghrelin-receptor agonist)
An early growth-hormone-releasing hexapeptide notable in research for a pronounced appetite-stimulating (hunger) effect alongside GH release.
Growth-hormone-releasing peptide (ghrelin-receptor agonist)
A potent synthetic GH-releasing hexapeptide, structurally related to GHRP-6, additionally studied for cardiovascular-tissue effects in preclinical models.
Pegylated IGF-1 splice variant (Mechano Growth Factor)
A pegylated form of Mechano Growth Factor, a splice variant of IGF-1 linked to muscle repair. Human data are limited and its use is investigational.
Recombinant follistatin isoform (glycoprotein)
A recombinant isoform of follistatin, a natural inhibitor of myostatin, studied for its potential to increase muscle mass. Most human work uses gene therapy rather than the injected protein.
Orally active non-peptide ghrelin receptor (GHS-R1a) agonist / growth hormone secretagogue
MK-677 (Ibutamoren) is an orally active growth hormone secretagogue that mimics ghrelin at the GHS-R1a receptor. Despite being grouped with research peptides, it is a small non-peptide molecule taken by mouth rather than injected. It remains investigational and is not an approved drug in the United States.
Recombinant peptide hormone (191-amino-acid growth hormone)
Somatropin is recombinant human growth hormone, the 191-amino-acid hormone itself rather than a secretagogue. It is FDA-approved across several growth-hormone-deficiency and growth-failure indications and is the hormone that peptides such as sermorelin, CJC-1295, and the GHRPs prompt the pituitary to release. Because it is the native hormone, its effects and risks are comparatively well characterized.
IGF-1 splice-variant peptide (IGF-1Ec)
MGF (Mechano Growth Factor) is a splice variant of IGF-1 known as IGF-1Ec, expressed transiently by muscle after mechanical loading or damage. The non-pegylated form described here is very short-acting and is distinct from the stabilized PEG-MGF variant. Evidence is preclinical and it is not an approved therapeutic.
Recombinant Fc-fusion decoy receptor (ActRIIB-Fc)
ACE-031 (ramatercept) is a fusion protein linking the activin receptor type IIB extracellular domain to an antibody Fc region, designed to trap myostatin and related ligands and thereby increase muscle mass. It reached early human trials, including in boys with Duchenne muscular dystrophy, but development was halted over vascular safety signals. It is investigational and not approved.
In-depth, research-framed reading for this category.
Educational summary only. Dosing figures describe how these compounds appear in the research literature and research-community references — they are not a personal treatment plan or a recommendation for human use. For laboratory research use only.
