Ipamorelin: what makes this GH secretagogue selective
A five–amino-acid peptide that, in animal studies, raised growth hormone without the cortisol rise.
TL;DR
- Ipamorelin is a five–amino-acid peptide that nudges your pituitary to release growth hormone.
- In published animal studies it did not raise cortisol (the stress hormone) the way older secretagogues did.
- It is often discussed alongside CJC-1295, which works on a different pathway. Long-term human data are limited.
What it is
Ipamorelin is a synthetic peptide built from five amino acids. It belongs to a family called growth hormone secretagogues (in plain English: molecules that prompt the pituitary gland to release growth hormone). The body's natural version of this signal is ghrelin — the same peptide that tells you you're hungry. Ipamorelin copies the growth-hormone-releasing part of ghrelin's job; in animal studies it did so without the cortisol rise seen with older copies. That selectivity is the headline.
How it works
Picture the pituitary gland as a small light switch high in your brain. Ghrelin can flip that switch, but it also flips a few others — appetite, cortisol, prolactin. Ipamorelin docks at the same switch ghrelin uses (the GHSR-1a receptor, the ghrelin receptor), but in animal studies it did not flip the cortisol switch. The result was a pulse of growth hormone without the cortisol bump (Raun et al., Eur J Endocrinol, 1998). Cortisol is your body's main stress hormone. Whether the animal finding holds in people over the long term has not been shown.
Who asks about it
People come to ipamorelin after reading claims about growth hormone and recovery, sleep, or body composition, or about older secretagogues like GHRP-2 or GHRP-6, which raised cortisol in animal studies. It is also often named alongside CJC-1295 online.
What the research says
In a foundational 1998 paper, ipamorelin produced a growth hormone release similar to GHRP-6 but without raising cortisol or prolactin in rats and pigs (Raun et al., 1998). Most evidence is short-term; long-term human outcomes remain understudied.
What to know
Reported effects include injection-site reactions and short-lived flushing. Long-term safety in people has not been established. Compounded ipamorelin is not FDA-approved. As of September 14, 2026, ipamorelin is not in any FDA 503A category and is not on the 503A bulks list.
The Halftime POV
Ipamorelin is the kind of tool that earns its place by what it doesn't do: in animal studies, it raised growth hormone without a cortisol bump or a prolactin shift. That is a real finding in animals. It is not evidence that ipamorelin helps adults whose growth hormone has declined with age, and long-term human data are limited.
Related reading:
- CJC-1295: what this modified GHRH peptide is
- CJC-1295 and ipamorelin: why the two are discussed together
- What are peptides? A plain-English primer
FAQ
Q: What is ipamorelin? A: Ipamorelin is a five–amino-acid peptide that prompts the pituitary gland to release growth hormone. It is called selective because, in published animal studies, it did not raise cortisol the way older secretagogues did.
Q: Is ipamorelin FDA-approved? A: No. Ipamorelin is not FDA-approved as a finished drug product. Compounded ipamorelin is not FDA-approved. As of September 14, 2026, ipamorelin is not in any FDA 503A category and is not on the 503A bulks list.
Q: How is ipamorelin different from CJC-1295? A: Both push growth hormone, but they pull different levers. CJC-1295 mimics the upstream signal (GHRH). Ipamorelin mimics ghrelin, the body's hunger signal. This article cites no human study of the two together.
Q: Does ipamorelin make you hungry? A: The studies behind ipamorelin's selectivity did not measure appetite, so the answer is not settled.
Disclaimer
This article is educational and is not medical advice. Compounded medications are not FDA-approved.
Sources
This article discusses compounds whose FDA compounding status has been under review (see our FDA categorization explainer). This article is provided for educational purposes only and does not constitute medical advice or an offer to sell.
Frequently asked questions
What is ipamorelin?
Ipamorelin is a five–amino-acid peptide that prompts the pituitary gland to release growth hormone. It is called selective because, in published animal studies, it did not raise cortisol the way older secretagogues did.
Is ipamorelin FDA-approved?
No. Ipamorelin is not FDA-approved as a finished drug product. Compounded ipamorelin is not FDA-approved. As of September 14, 2026, ipamorelin is not in any FDA 503A category and is not on the 503A bulks list.
How is ipamorelin different from CJC-1295?
Both push growth hormone, but they pull different levers. CJC-1295 mimics the upstream signal (GHRH). Ipamorelin mimics ghrelin, the body's hunger signal. This article cites no human study of the two together.
