CJC-1295 does one thing: it makes the pituitary release more of the body's own growth hormone, for days at a time. It does not deliver growth hormone, and it does not switch off the pituitary's own control.
CJC-1295 is a long-acting GHRH analog. What it does is bind the GHRH receptor on the pituitary and prompt the gland to release more of its own growth hormone, which the liver converts into IGF-1 [1]. The reason people ask specifically about CJC-1295 rather than other GHRH analogs is duration. A single dose keeps GH and IGF-1 elevated for days, not minutes.
- CJC-1295 is a modified GHRH fragment that binds the pituitary GHRH receptor and raises the body's own GH [1]
- It does not deliver growth hormone directly, the way injected HGH does
- The DAC version bioconjugates to serum albumin, extending its half-life to an estimated 5.8 to 8.1 days [1][2]
- A single dose raised GH 2 to 10-fold for 6 days or more and IGF-1 for 9 to 11 days [2]
- Normal GH pulsatility continues; basal GH rises about 7.5-fold while pulses keep their size [3]
- It is not FDA-approved, is flagged by the FDA for compounding, and is banned in sport [5][6]
What CJC-1295 Does, Step by Step
- Binds the GHRH receptor on the anterior pituitary, the same receptor native GHRH uses [1]
- Prompts the pituitary to release more of its own growth hormone in pulses
- The liver converts that GH into IGF-1, the downstream marker that tracks the effect [2]
- The DAC version stays bound to serum albumin, so the signal lasts for days rather than minutes [1]
The mechanism is upstream stimulation, not replacement. That distinction is the whole point of a GHRH analog. Injected HGH puts growth hormone directly into the blood, and the pituitary reads the high level and quiets down. CJC-1295 asks the pituitary to do the work, so the gland's own feedback control stays in the loop.
The DAC Is Why It Lasts for Days
The long duration comes from a single design feature. CJC-1295 with DAC, the drug affinity complex, carries a chemical group that bioconjugates to serum albumin in the blood [1]. Albumin circulates for weeks, so tethering the peptide to it shields the peptide from the enzymes that would otherwise clear it in minutes.
The measured result is long. In healthy adults, a single dose raised mean plasma GH 2 to 10-fold for 6 days or more and IGF-1 1.5 to 3-fold for 9 to 11 days, and repeated dosing kept IGF-1 above baseline for up to 28 days, with an estimated half-life of 5.8 to 8.1 days [2]. For contrast, sermorelin and the DAC-free version of the peptide clear in about 4 minutes [4].
Does It Flatten the GH Pulse? No
A common worry is that a peptide raising GH for days must erase the natural pulse pattern the GH axis runs on. The study built to test that found the opposite. One week after dosing, GH pulse frequency and magnitude were unchanged while basal GH rose about 7.5-fold [3]. Pulses continue at their normal size, and the trough between them rises.
What that means in practice is that CJC-1295 lifts the floor rather than removing the rhythm. Whether a chronically raised basal GH level matters over years has not been studied in humans, which is the honest limit on the mechanism.
What CJC-1295 Does Not Do
- It does not deliver growth hormone. It stimulates the pituitary to make its own [1]
- It does not suppress the pituitary, because somatostatin feedback stays intact
- It does not act quickly and clear quickly. Its whole distinction is multi-day action [2]
- It is not a weight-loss drug, and no trial shows body-composition outcomes for it
- It is not FDA-approved. Human data come from a single 2006 trial, and the FDA has identified serious adverse events for it [5]
How This Shapes Its Use
Because CJC-1295 raises IGF-1 for days at a time, the number that tells you what it is doing is a baseline IGF-1 and a retest, not how a dose feels. A result driven above the age-adjusted range is a reason to reduce the dose, since the side effects of any GHRH analog track with how high IGF-1 goes. A program that dispenses CJC-1295 without a baseline draw has skipped the measurement that makes its long action safe to run.
The regulatory picture belongs in any honest answer to what it does. FDA states it has identified serious adverse events for CJC-1295 and that the clinical data are limited [5], and it is prohibited in sport at all times [6]. It is dispensed as a compounded preparation, not an approved drug.
CJC-1295 raises IGF-1 for days, which makes a starting number and a retest more useful, not less. SystemLabs tests IGF-1 before prescribing and formulates CJC-1295 on clinical indication, so the dose is set against your labs rather than a fixed chart.
Frequently Asked Questions
What does CJC-1295 do?
CJC-1295 binds the GHRH receptor on the pituitary and prompts it to release more of the body's own growth hormone, which the liver converts into IGF-1 [1]. It does not deliver growth hormone directly. Its distinguishing feature is duration: a single dose keeps GH and IGF-1 elevated for days [2].
How long does CJC-1295 stay in your system?
The DAC version has an estimated half-life of 5.8 to 8.1 days, because it bioconjugates to serum albumin and resists rapid clearance [1][2]. A single dose raised GH for 6 days or more and IGF-1 for 9 to 11 days, and repeated dosing kept IGF-1 above baseline for up to 28 days [2].
Does CJC-1295 increase growth hormone or IGF-1?
Both, and it does so by stimulation rather than replacement. A single dose raised mean plasma GH 2 to 10-fold and IGF-1 1.5 to 3-fold in healthy adults [2]. The GH comes from the person's own pituitary, and IGF-1 is the liver's downstream response that a program tracks with lab work.
Does CJC-1295 stop your body's natural GH pulses?
No. The study designed to test that found GH pulse frequency and magnitude unchanged one week after dosing, while basal GH rose about 7.5-fold [3]. It lifts the baseline between pulses rather than erasing the rhythm. Whether a chronically raised basal GH matters over years has not been studied in humans.
Is CJC-1295 the same as sermorelin?
Both are GHRH analogs that act on the same pituitary receptor, but the duration differs sharply. Sermorelin clears in about 4 minutes and mirrors the natural nightly pulse [4], while CJC-1295 with DAC stays active for days [2]. Sermorelin is dosed nightly; CJC-1295 is dosed far less often.
Is CJC-1295 FDA-approved?
No. CJC-1295 is not an FDA-approved drug and is dispensed only as a compounded preparation. Human data come from a single 2006 trial, and the FDA has identified serious adverse events for it and states the clinical data are limited [5]. It is also prohibited in sport at all times [6].
References
- 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, 2005. PMID: 15817669. https://pubmed.ncbi.nlm.nih.gov/15817669/
- 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 & Metabolism, 2006. PMID: 16352683. https://pubmed.ncbi.nlm.nih.gov/16352683/
- Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog Journal of Clinical Endocrinology & Metabolism, 2006. PMID: 17018654. https://pubmed.ncbi.nlm.nih.gov/17018654/
- Incorporation of D-Ala2 in growth hormone-releasing hormone-(1-29)-NH2 increases the half-life and decreases metabolic clearance in normal men Journal of Clinical Endocrinology & Metabolism, 1994. PMID: 7962295. https://pubmed.ncbi.nlm.nih.gov/7962295/
- Certain bulk drug substances for use in compounding that may present significant safety risks FDA.gov, Human Drug Compounding, 2026. Content current as of 04/22/2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
- The 2026 Prohibited List: International Standard, section S2.2.4 growth hormone releasing factors World Anti-Doping Agency, 2026. WADA 2026 Prohibited List. https://www.wada-ama.org/en/resources/2026-prohibited-list
