# CJC-1295: Research Overview — Peptide Cycles > A data-forward literature summary of CJC-1295, a long-acting GHRH-receptor analog studied for sustained GH/IGF-1 elevation. Covers mechanism, pharmacokinetic protocols, reported effects, and cited safety cautions. A modified GHRH-receptor analog engineered to extend a single dose's effect on growth hormone and IGF-1 from minutes to days — with a DAC variant and a shorter no-DAC variant that behave very differently. ## The short version CJC-1295 is a lab-made version of growth-hormone-releasing hormone (GHRH), the natural brain signal that tells the pituitary gland to release growth hormone (GH). Four small chemical changes make it resist breakdown in the body, and in its "DAC" form it also attaches to a blood protein called albumin, which stretches its effect from minutes to days. A second version without that attachment, often called "Modified GRF 1-29" or no-DAC, wears off much faster. In human studies, a single dose of CJC-1295 raised growth hormone two- to ten-fold for six or more days and raised IGF-1 — a second hormone the liver makes in response to GH — for nine to eleven days; with repeated dosing, IGF-1 stayed elevated for up to 28 days [4]. It has never been approved as a medicine anywhere. All figures on this page come from published pharmacology studies in small groups of healthy adults or from laboratory identification work, not from any large clinical trial, and none of it is a recommendation for how a person should use anything. ## What it is CJC-1295 is built on the first 29 amino acids of human GHRH — hGRF(1-29) — with four substitutions (D-alanine at position 2, glutamine at 8, alanine at 15, and leucine at 27) that stabilize its alpha-helix shape and block the enzymes (dipeptidyl peptidase-IV, plus deamidation and oxidation pathways) that normally degrade native GHRH within minutes. In the "DAC" (Drug Affinity Complex) form, a C-terminal lysine carries a maleimidopropionyl linker that forms a covalent bond with a free thiol group on Cys34 of circulating serum albumin — chemically welding the peptide to one of the most abundant, longest-lived proteins in blood, which is what stretches its effective duration toward that of albumin itself. The no-DAC form, sometimes labeled "Modified GRF 1-29," keeps the four stabilizing substitutions but skips the albumin-binding chemistry, so it clears the body in minutes to hours rather than days. CJC-1295 was independently identified in a black-market context: a 2010 analytical chemistry paper used high-resolution liquid chromatography-tandem mass spectrometry to confirm CJC-1295 as the active ingredient in an unlabeled "GHRH" product seized in an anti-doping investigation [2] — one of the few pieces of definitive, non-industry-sourced identification of this molecule in circulation. ## How it works CJC-1295 binds the growth-hormone-releasing hormone receptor (GHRHR) on somatotroph cells in the anterior pituitary, activating the Gs/cAMP/protein-kinase-A signaling cascade that is the normal trigger for GH synthesis and release. Because this is the same receptor and the same signaling pathway that native GHRH uses, CJC-1295 does not introduce a new mechanism into the GH axis — it extends how long an existing one stays switched on. Downstream, GH released from the pituitary travels to the liver, where it stimulates IGF-1 production; IGF-1 in turn carries out much of GH's growth-promoting and metabolic activity throughout the body. A notable pharmacological detail is that this sustained receptor stimulation does not appear to override the body's normal pulsatile GH rhythm. A human pharmacokinetic study found that a single 60 or 90 microgram/kg dose raised trough (basal) GH roughly 7.5-fold and mean GH by about 46%, with IGF-1 rising about 45% a week later — but the frequency and amplitude of the underlying GH pulses were statistically unchanged, indicating the body's normal pulse-generating machinery kept operating even under continuous GHRH-receptor stimulation [5]. ## What the research shows *Mechanism and context.* A 2025 review in a leading endocrinology journal synthesizes the pharmacology of GHRH and its synthetic analogs — the drug class that includes CJC-1295, sermorelin, and tesamorelin — covering receptor signaling and the design logic behind long-acting variants, and situates CJC-1295 within the current therapeutic and investigational landscape for this compound class [1]. *Dose-dependent GH and IGF-1 elevation.* In healthy adults aged 21-61, single subcutaneous doses of 30 or 60 micrograms/kg produced dose-dependent 2- to 10-fold increases in mean plasma GH sustained for 6 or more days, and 1.5- to 3-fold increases in IGF-1 sustained for 9-11 days. With repeated dosing, IGF-1 remained above baseline for up to 28 days. The same study modeled an elimination half-life of 5.8-8.1 days for CJC-1295 itself [4]. *Pulsatility is preserved.* In healthy men aged 20-40, a single 60 or 90 microgram/kg dose raised basal (trough) GH approximately 7.5-fold and mean GH by roughly 46%, with IGF-1 up about 45% one week post-dose — while the frequency and magnitude of pulsatile GH secretion were statistically unaltered from baseline, meaning the GH axis kept its normal pulse pattern under sustained GHRH-receptor stimulation [5]. *Downstream biomarker signature.* In 11 healthy young men, CJC-1295 shifted the serum proteome in a reproducible pattern — decreased apolipoprotein A1 and a transthyretin isoform, increased a C-terminal albumin fragment and immunoglobulin/beta-hemoglobin species — and the immunoglobulin/albumin-fragment signal correlated linearly with IGF-1, suggesting candidate serum biomarkers of GH/IGF-1 axis activation beyond IGF-1 measurement alone [3]. *Confirmed identity in circulation.* High-resolution LC-MS/MS analysis definitively identified CJC-1295 as the active ingredient in an unlabeled pharmaceutical preparation seized in an anti-doping context, confirming that the molecule circulating outside formal channels matches the compound characterized in the pharmacology literature [2]. ## Reported effects, cautions & safety The findings above come from a small number of controlled pharmacology studies. Separately, people using CJC-1295 in research-use and wellness-adjacent communities describe a fairly consistent set of subjective effects — this is anecdotal, not clinical evidence, and none of it should be read as a verified outcome or as guidance for how to use anything. *Reported benefits (anecdotal, not clinical evidence):* The most consistently described effect is deeper, more restful sleep, often noticed within the first week — a plausible pattern given that growth hormone is released mainly during deep sleep. Faster recovery from training and reduced soreness are also frequently described, along with gradual fat loss (especially around the midsection) that people report emerging around weeks three to six, and a leaner look with better perceived muscle retention when paired with consistent training. More daytime energy and sharper focus are described occasionally, generally attributed to better sleep rather than a direct effect. *Reported adverse effects (anecdotal, not clinical evidence):* Water retention, bloating, and facial or hand puffiness are the most commonly reported downside, and are widely described as more pronounced with the long-acting DAC form than with the short-acting no-DAC form — consistent with DAC keeping GH elevated for days rather than hours. Tingling or numbness in the fingers, often compared to mild carpal tunnel, is frequently reported and is generally attributed to fluid pressing on wrist nerves. Injection-site redness or soreness, occasional flushing or a warm "head rush" shortly after dosing (reported more with the short-acting form), and fatigue or headache are also described, along with occasional reports of higher blood sugar during sustained use. *Cited cautions from the clinical literature:* - **Not approved for human use anywhere.** Human evidence is limited to a small number of early pharmacology studies; there is no large or long-term trial establishing safety or effectiveness in healthy adults [4][2]. - **Sustained IGF-1 elevation and a theoretical cancer-risk association.** A large epidemiologic meta-analysis linked higher circulating IGF-1 to a modestly increased risk of certain cancers; because the DAC form keeps IGF-1 elevated for days per dose, this is a mechanism-based concern for anyone with a personal or family cancer history. - **Fluid retention and nerve-compression effects.** Growth hormone causes the kidneys to retain sodium and water, the likely driver behind commonly reported puffiness and tingling. - **Effects on blood sugar and insulin sensitivity.** Growth hormone is glucose-sparing; a clinical pharmacology study of a GHRH analog documented measurable effects on insulin sensitivity. - **Immunogenicity flagged by regulators.** 2024 FDA briefing materials for a compounding-pharmacy advisory committee cited immunogenicity and other safety concerns as part of the basis for not recommending CJC-1295 for a compounding bulk-substances list. - **A discontinued development program and a cited death during that era.** The original long-acting CJC-1295 DAC development program ran a Phase 2 trial in HIV-associated visceral obesity that was discontinued; a patient death from that development era is frequently cited alongside the halted program, though the public record does not establish that CJC-1295 caused it. - **DAC and no-DAC forms are routinely confused**, despite behaving very differently — the DAC form remains active for days, the no-DAC form for minutes to hours — which matters directly for interpreting any reported effect or duration. - **Prohibited in sport at all times** under the World Anti-Doping Agency's Section S2 category for peptide hormones and growth factors, with established detection methods. ## Where it fits in the Growth Hormone Axis CJC-1295 occupies the upstream end of the GH axis on this desk — it acts at the same receptor and pathway the body already uses to trigger GH release, and its defining pharmacological trick is duration rather than a new mechanism [4][5]. [Ipamorelin](/ipamorelin) reaches the same downstream hormone (GH) through an entirely separate receptor, which is the pharmacological rationale for studying the two together. [MOTS-c](/mots-c) sits further downstream still, acting on cellular energy-sensing machinery rather than the pituitary-hormone signaling that both CJC-1295 and ipamorelin depend on. See the [comparison page](/compare) for how the three research protocols and evidence bases line up side by side. ![CJC-1295 research illustration — abstract pituitary-signaling motifs in dim plum and magenta](/images/cjc-1295.webp) --- A data desk for Growth Hormone Axis peptide research — every number sourced to its study design, no doses recommended, nothing for sale.