GH axis & body composition

Ipamorelin

A five-amino-acid peptide that activates the ghrelin receptor and prompts the release of growth hormone.

A different route to growth-hormone release.

Ipamorelin acts through the ghrelin receptor, also called GHS-R1a. That receptor can signal the pituitary gland to release growth hormone. CJC-1295 works through a different receptor, GHRH.

How it works.

Ghrelin receptor: Ipamorelin activates GHS-R1a, a receptor involved in growth-hormone secretion.
Pituitary response: Activation promotes release of growth hormone from pituitary cells.
GH–IGF-1 axis: Released growth hormone participates in downstream IGF-1 signaling and metabolic regulation.

Useful terms

Secretagogue: A substance that stimulates the release of another substance.
Pentapeptide: A peptide containing five amino acids.
Pituitary: A small gland at the base of the brain that releases several hormones.

Results.

Human infusion study

A brief pulse of growth hormone.

In healthy male volunteers, a short infusion produced a growth-hormone pulse that peaked about 40 minutes after the infusion began, then declined. The study measured hormone release and how the peptide moved through the body.

Human hormone response · Gobburu et al., 1999

Risks, concerns & drawbacks.

Duration & route: The hormone study used a short intravenous infusion. A separate postoperative trial used intravenous treatment for up to seven days. Side-effect rates during months of subcutaneous use are not established by those studies.
Combining peptides: The cited human studies tested ipamorelin alone. They do not describe the results or side-effect rates of a CJC-1295–ipamorelin combination.

Infusion study · 1999 Postoperative trial · 2014