The Ipamorelin Studies, Figure by Figure

Before the figures

This is the Ipamorelin research page — the data, kept plain. Here is the map before the detail.

The strongest result is old and clean: in 1998, ipamorelin was shown to release growth hormone (GH) hard while leaving the stress hormone cortisol flat ^[1]. The most useful human number is its half-life — about 2 hours ^[2]. The most important human result is a disappointment: the one efficacy trial failed ^[3]. The animal data are real but small — bone growth in rats ^[4], weight protection in ferrets ^[5].

Read the rest as a careful person would: large, repeatable effects in animals; one clean human pharmacology study; and an efficacy record that, in humans, is thin and negative. The mechanism is well-characterized. The clinical payoff has not been demonstrated.

The founding selectivity result

The defining study is Raun et al., 1998 — titled, plainly, "Ipamorelin, the first selective growth hormone secretagogue" ^[1]. Ipamorelin released GH potently in rat pituitary cells, anaesthetized rats, and conscious swine (swine ED50 2.3 ± 0.03 nmol/kg, versus 3.9 nmol/kg for GHRP-6) ^[1].

The selectivity is the headline: ACTH and cortisol did not rise above the GHRH baseline even at doses more than 200-fold above the GH ED50 ^[1]. Prolactin stayed flat. This was the first GHS to cleanly separate the GH signal from the adrenocortical and prolactin axes. The characterization was acute, not chronic — a point worth keeping in view when chronic-use claims are made.

A large-animal study in swine independently confirmed the selective GH-release profile ^[7].

Human pharmacokinetics

The human PK/PD study (Gobburu et al., 1999) gave healthy male volunteers five 15-minute IV infusions across 4.21–140.45 nmol/kg, n=8 per dose level ^[2]. Kinetics were dose-proportional: terminal half-life about 2 hours, clearance 0.078 L/h/kg, steady-state volume of distribution 0.22 L/kg ^[2]. The GH response was a single discrete pulse peaking near 40 minutes (0.67 h) ^[2].

This is one of the only human datasets on ipamorelin, and it is pharmacology, not efficacy — it describes how the molecule moves and how GH responds, not whether any outcome improves.

Does cjc-1295 ipamorelin work — the human efficacy record

On controlled human efficacy, the record is thin and negative. The only published Phase 2 RCT (Beck et al., 2014; NCT00672074) gave 114 bowel-resection patients 0.03 mg/kg IV twice daily for up to 7 days and missed its primary endpoint: median time to first tolerated meal 25.3 h on ipamorelin vs 32.6 h on placebo, p=0.15 ^[3]. Treatment-emergent adverse events occurred in 87.5% of the ipamorelin arm vs 94.8% of placebo — no ipamorelin-specific safety signal in that short window, but no efficacy either ^[3].

So: does cjc-1295 ipamorelin work? For pure ipamorelin, the one human efficacy trial failed ^[3]. For the CJC-1295 + ipamorelin combination specifically, there is no controlled human outcome trial at all — its case rests on the separate single-agent pharmacology of a ghrelin mimetic and a GHRH analog, not on a tested product.

Animal efficacy and body composition

In adult female rats, subcutaneous ipamorelin (18, 90, 450 microgram/day, divided three times daily, 15 days) dose-dependently raised longitudinal bone-growth rate from 42 micrometers/day at vehicle to 44, 50, and 52 micrometers/day — with no change in total IGF-1, IGFBPs, or bone-turnover markers, implying a partly local, GH-pulse-driven skeletal effect ^[4].

In the freshest study, a 2024 ferret model, intraperitoneal ipamorelin (1–3 mg/kg) inhibited cisplatin-induced body-weight loss by about 24% in the delayed phase, though it had no anti-emetic effect ^[5]. An ipamorelin-derived oral analog (NN703) produced significant body-weight gain over 14 days in rats, confirming the class alters body composition through sustained GH-axis activation ^[8].

GH-independent adiposity is also on record: twice-daily subcutaneous ipamorelin raised body weight in both GH-deficient and GH-intact mice ^[14] — part of the effect bypasses the GH axis entirely.

The class-level safety signal

The honest counterweight to the mechanism story is a chronic-toxicity signal at the receptor-class level. A 28-day integrated safety study of GSK894281, a different GHS-R1a agonist, found dose-dependent myocardial degeneration and necrosis in rats — visible on histopathology and electron microscopy, with elevated heart-type fatty-acid-binding protein at the top doses ^[6].

Ipamorelin itself was not the tested compound, and no equivalent long-duration cardiovascular study of ipamorelin exists. But the signal is the reason chronic systemic GHS dosing warrants scrutiny: the selectivity that makes ipamorelin clean on cortisol says nothing about long-term cardiac safety, which has simply not been studied.

Ipamorelin cjc-1295

The ipamorelin cjc-1295 pairing combines a ghrelin-receptor (GHS-R1a) agonist with a GHRH analog — two independent mechanisms converging on the same GH pulse ^[1]. The pharmacological rationale is real: a ghrelin mimetic and a GHRH analog push GH through separate receptors, so co-administration can amplify the pulse more than either alone. What is missing is a trial. No published controlled study tests the combination for any outcome; the popular stack is supported by single-agent pharmacology, not by combination data.

What is cjc 1295 ipamorelin

What is cjc 1295 ipamorelin? It is the two-peptide combination promoted in research-use communities, pairing ipamorelin (the selective ghrelin-receptor GH-releasing peptide profiled across this site ^[1]) with CJC-1295, a long-acting GHRH analog. This site reads pure ipamorelin; the combination is named here only to draw the line clearly. The ghrelin-receptor arm and the GHRH-receptor arm are mechanistically distinct, and no controlled human trial has tested them together as a product.

Mechanistic context

Two further studies sit behind the appetite and metabolic questions. GHRP-class compounds partly act by triggering endogenous ghrelin: GHRP-6 and the ipamorelin-derived NN703 accumulate in the gastric mucosa after IV dosing, and gastric resection cut GHRP-6-induced GH release by 60–70% ^[9]. And ipamorelin's direct pancreatic action — insulin release from normal and diabetic rat tissue, blocked by calcium-channel and adrenergic/cholinergic antagonism — marks a GH-independent metabolic side-channel ^[13].

The glucocorticoid result rounds it out: methylprednisolone did not blunt the acute GH response to ipamorelin in rats, and the combination raised IGF-1 and improved body-weight recovery versus steroid alone ^[11]. The GH door holds open under steroid load.