Endocrinology · CJC-1295 / Ipamorelin
CJC-1295 and ipamorelin as tools for studying the GH axis
September 26, 2026 · 1 min read · Models: Mouse, Rat, Pituitary cell culture
CJC-1295 is a GHRH analog designed to bind serum albumin, and ipamorelin is a selective agonist of the ghrelin receptor (GHS-R1a). Preclinical work uses them to separate the two main stimulatory inputs to pituitary growth-hormone release.
A summary of published research for scientific reference. It is not medical advice and does not describe or endorse use in humans or animals. Findings from cell culture and animal models often do not carry over to other systems.
Two pathways to growth-hormone release
Pituitary somatotrophs release growth hormone (GH) in response to hypothalamic GHRH, acting via the GHRH receptor and cAMP. Ghrelin-receptor agonists act through a separate Gq-coupled pathway. Somatostatin opposes both. Selective agonists for each input let researchers study their individual and combined contributions.
Ipamorelin
Raun and colleagues (European Journal of Endocrinology, 1998) described ipamorelin as the first growth-hormone secretagogue to be selective in vivo. In rat and swine models it released GH without the rises in ACTH and cortisol seen with earlier secretagogues such as GHRP-6, so it is useful for isolating GH-axis effects.
CJC-1295
CJC-1295 is a modified GHRH(1–29) with a reactive “drug affinity complex” (DAC) linker that binds albumin covalently, greatly extending its half-life. Alba and colleagues (American Journal of Physiology – Endocrinology and Metabolism, 2006) used it in GHRH-knockout mice, which made it a tool for comparing sustained with pulsatile GHRH signaling.
Design notes
Formulations sold as “CJC-1295” sometimes lack the DAC moiety (often called “modified GRF 1–29”). The two behave very differently pharmacokinetically. The exact structure should be confirmed by identity testing and stated in methods sections.
References
- Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552–561.
- Alba M, Fintini D, Sagazio A, et al. Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. Am J Physiol Endocrinol Metab. 2006;291(6):E1290–E1294.