CJC-1295 elevated growth hormone 2- to 10-fold in a published human trial — here is what the research actually measured.

What Is the CJC-1295 Peptide?

CJC-1295 is a 29-amino-acid synthetic analog of growth hormone-releasing hormone (GHRH), first developed by ConjuChem Biotechnologies. It was designed as a stabilized version of the native GHRH(1-29) sequence — the active fragment of the hypothalamic peptide that tells the anterior pituitary to release growth hormone ^[4]. Four amino acid substitutions (Ala2, Gln8, Ala15, Leu27) protect it from rapid degradation by the enzyme DPP-IV, which destroys the native peptide at the 2-3 amino acid bond within minutes of entering circulation ^[11].

The CJC-1295 DAC form adds a further modification: a maleimidopropionic acid-lysine group at the C-terminus that covalently bonds to free thiol groups on circulating serum albumin. Albumin is the blood's principal transport protein and circulates with a half-life of roughly 19 days. By hitchhiking on albumin, CJC-1295 DAC extends its own plasma half-life from approximately 30 minutes (no-DAC form) to 5.8–8.1 days in human subjects ^[1]. That pharmacokinetic gap — 30 minutes vs. nearly a week — is the central structural story of the CJC-1295 literature.

CJC-1295 is not FDA-approved for any indication. It was investigated in Phase I/II human clinical trials for adult growth hormone deficiency and metabolic conditions. A Phase II trial in HIV patients with visceral obesity was halted in 2006 following an adverse event ^[18]. The FDA placed CJC-1295 on the 503A bulk drug substance no-go list in 2024, citing lack of clinical necessity relative to approved alternatives.

What Does CJC-1295 Do to the Body?

CJC-1295 binds to GHRH receptors on somatotroph cells in the anterior pituitary. These are the cells responsible for synthesizing and secreting growth hormone (GH). Binding activates the Gs-protein signaling cascade: adenylate cyclase is turned on, intracellular cAMP rises, protein kinase A is activated, voltage-gated calcium channels open, and stored GH secretory granules are released ^[15]. Downstream, the liver responds to elevated GH by producing IGF-1, the primary anabolic mediator of GH signaling.

Critically, a 2006 study by Ionescu and Frohman demonstrated that this process preserves pulsatile GH secretion ^[3]. A single injection of CJC-1295 at 60 or 90 mcg/kg raised basal GH levels 7.5-fold and increased mean GH secretion by 46%, while GH pulse frequency and pulse magnitude remained unaltered. The pituitary continued to release GH in its natural episodic bursts — the elevation was in the floor beneath those pulses, not a replacement of the pulsatile pattern.

For the CJC-1295 mechanism of action in detail, including the cryo-EM structural data on GHRH receptor binding, see the research page.

CJC-1295 Research Findings: Studied Benefits

The published CJC-1295 literature documents five distinct outcome categories in preclinical and early clinical research.

GH and IGF-1 elevation. In the Teichman et al. Phase I/II trial, single subcutaneous doses of 30–125 mcg/kg produced dose-dependent 2- to 10-fold increases in mean plasma GH concentrations sustained for six or more days, and IGF-1 elevation sustained 9–11 days ^[1]. After multiple injections, mean IGF-1 remained above baseline for up to 28 days.

Body composition and growth in GH-deficient models. Once-daily CJC-1295 administration at 2 micrograms per injection normalized body weight, body length, lean mass, fat mass, and long bone lengths (femur and tibia) in GHRH knockout mice — an established model of GH deficiency ^[5]. Less frequent dosing (every 48 or 72 hours) produced only partial normalization, establishing a dose-frequency relationship.

Serum proteome changes. CJC-1295 administration in 11 healthy adult men produced measurable serum protein profile changes one week post-injection, including decreased apolipoprotein A1 and transthyretin isoforms and increased beta-hemoglobin and albumin fragments ^[6]. IGF-1 levels correlated linearly with an albumin fragment marker — a proteomic signature of GH/IGF-1 axis activation.

Ipamorelin synergy. In vitro studies showed that co-activation of GHRH receptors (CJC-1295 target) and GHSR receptors (ipamorelin target) produced a cAMP response approximately twice that of GHRH receptor activation alone, via proposed direct receptor-receptor interaction ^[8]. This mechanistic synergy is the basis for the CJC-1295 ipamorelin stack research.

Bone and muscle endpoints (ipamorelin). As the primary research partner in the stack literature, ipamorelin produced dose-dependent increases in longitudinal bone growth rate (42 to 44–52 micrometers per day) in adult rats over 15 days ^[9], and counteracted glucocorticoid-induced bone loss with a 4-fold increase in periosteal bone formation rate ^[10]. These findings inform the joint study rationale, though no combined CJC-1295/ipamorelin human trial has been published.

Frequently Asked Questions About CJC-1295

The frequently asked questions about CJC-1295 page covers 28 questions drawn from published PAA, Quora, and search-suggestion data — including the DAC vs no-DAC pharmacokinetic differences, CJC-1295 side effects documented in studies, the ipamorelin combination, regulatory status, and the half-life question. Peer-reviewed CJC-1295 references lists every citation used across this site with DOI and PubMed links.