Growth Hormone Secretagogue
Quick Definition
A growth hormone secretagogue is a substance that stimulates the pituitary to release endogenous growth hormone. The category includes GHRH analogs (sermorelin, tesamorelin, CJC-1295) acting through the GHRH receptor, and GHRPs (ipamorelin, MK-677) acting through the ghrelin receptor pathway.
In Depth
Growth hormone secretagogues stimulate endogenous growth hormone release through one of two receptor pathways:
GHRH (Growth Hormone Releasing Hormone) analogs mimic the hypothalamic GHRH signal at the pituitary. Examples: - Sermorelin: 29-amino-acid GHRH analog. FDA-approved 1990, branded product withdrawn 2008. Currently available as compounded prescription. - Tesamorelin (Egrifta SV): FDA-approved for HIV-associated lipodystrophy. - CJC-1295: Modified GHRH analog with extended half-life. Off-label, compounded.
GHRPs (Growth Hormone Releasing Peptides) act through the ghrelin receptor: - Ipamorelin: Selective GHRP without significant cortisol or prolactin effects. Off-label, compounded. - GHRP-2, GHRP-6, hexarelin: Older GHRPs with broader effects on appetite and other hormones. - MK-677 (ibutamoren): Oral non-peptide ghrelin receptor agonist.
The pulsatile GH release produced by these molecules differs from the sustained levels produced by exogenous recombinant human growth hormone (rHGH). The pulsatile pattern more closely resembles natural physiology.
Combination therapy with a GHRH analog plus a GHRP is common in off-label clinical practice. Combinations like CJC-1295 + ipamorelin are intended to stimulate both receptor pathways for a stronger and more reliable effect.
Clinical effects in healthy adults are modest. Long-term safety in healthy populations is not characterized. IGF-1 elevation has theoretical implications for cancer risk in susceptible patients. Glucose metabolism can be affected.
Most growth hormone secretagogues used clinically in the U.S. are either FDA-approved (tesamorelin) or compounded (sermorelin, CJC-1295/ipamorelin combinations). Research-grade peptides sold outside the regulated drug supply have variable quality and unclear regulatory status.
Related Terms
BPC-157
BPC-157 (Body Protection Compound-157) is a 15-amino-acid peptide derived from human gastric juice protein, marketed in the wellness and "research peptide" space for tissue healing. It is not FDA-approved and is not currently authorized for compounding for human use.
Sermorelin
Sermorelin is a 29-amino-acid GHRH (growth hormone releasing hormone) analog that stimulates the pituitary to release endogenous growth hormone. It was FDA-approved in 1990 for pediatric growth hormone deficiency but the branded product was withdrawn in 2008. It is currently available through compounding pharmacies for off-label adult use.
Peptide Therapy
Peptide therapy refers to the clinical or off-label use of short chains of amino acids (peptides) for various therapeutic purposes including growth hormone modulation, tissue healing, and metabolic effects. The clinical evidence base varies dramatically across specific peptides — from FDA-approved indications to research-only.