CJC-1295

What it is

CJC-1295 is a synthetic analog built on hGRF(1-29), the first 29 amino acids of growth hormone-releasing hormone (GHRH). Two different molecules circulate under the name: the form tested in the published human studies carries a "drug affinity complex" (DAC), a reactive linker that bonds the peptide to albumin in the blood and extends its half-life to roughly a week, while the "no-DAC" form, also sold as Modified GRF (1-29), lacks that linker. No published human trials of the no-DAC form were identified for this summary, so the human findings below apply only to the DAC form.

Mechanism of action

CJC-1295 acts on the GHRH receptor of pituitary somatotroph cells, the same receptor the body's own GHRH uses, prompting those cells to release growth hormone (GH). GH in turn drives production of insulin-like growth factor 1 (IGF-1), largely in the liver. Native GHRH survives only briefly in the blood, in part because the enzyme dipeptidyl peptidase-IV (DPP-IV) cleaves it at the N-terminus. CJC-1295 modifies the hGRF(1-29) sequence, and in the DAC form a maleimido linker binds the free thiol on cysteine-34 of serum albumin, so the peptide travels on albumin and is cleared slowly. Jetté et al. (2005) reported that these albumin bioconjugates resisted DPP-IV in vitro and stimulated GH release from rat pituitary cells. In humans, Ionescu and Frohman (2006) reported that GH continued to be released in pulses during this continuous receptor stimulation, rather than being replaced by a flat, constant elevation.

What it’s most studied for

Research on CJC-1295 has centered on one question: whether a single GHRH-analog injection can keep GH and IGF-1 raised for days rather than hours. That made it a research candidate for conditions marked by low GH output, and the FDA's 2024 compounding review evaluated it for growth hormone deficiency. The published human work measured hormone levels, pharmacokinetics and safety in healthy adults. Animal work in rats and in GHRH knockout mice examined whether sustained GHRH-receptor stimulation supports pituitary GH production and normal growth. Interest outside research settings focuses on body composition and recovery, but no published controlled trial has measured those outcomes with either form of CJC-1295.

Notable findings

Each finding carries the species or population it was observed in and the dose that study used. Doses are reported as research context, exactly as published. They are not guidance.

Study quality

Human data on CJC-1295 are limited to small, short phase 1 and physiology studies of the DAC form in healthy adults, published in 2006; no published controlled trial has tested either form for a clinical outcome, and no published human trials of the no-DAC form were identified. Teichman et al. (2006) was randomized, double-blind and placebo-controlled, but it measured hormone levels, pharmacokinetics and safety over 28 to 49 days, not body composition, strength or recovery. Animal evidence comes from rats and GHRH knockout mice. The human and mouse papers share several authors, so independent replication is thin. On safety, Teichman et al. reported no serious adverse reactions and described tolerability as best at the two lower doses tested; the long-term effects of keeping GH and IGF-1 raised for weeks have not been studied in published trials.

References

1. 1
   Teichman SL, Neale A, Lawrence B, et al. (2006). Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. Journal of Clinical Endocrinology and Metabolism. PMID 16352683
2. 2
   Ionescu M, Frohman LA (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology and Metabolism. PMID 17018654
3. 3
   Jetté L, Léger R, Thibaudeau K, et al. (2005). Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology. PMID 15817669
4. 4
   Alba M, Fintini D, Sagazio A, et al. (2006). Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. American Journal of Physiology. Endocrinology and Metabolism. DOI 10.1152/ajpendo.00201.2006
5. 5
   US Food and Drug Administration (2024). FDA Briefing Document: Pharmacy Compounding Advisory Committee (PCAC) Meeting, December 4, 2024 (AOD-9604, CJC-1295 and thymosin alpha-1 related bulk drug substances). FDA Pharmacy Compounding Advisory Committee.