Two different drugs are sold under the name CJC-1295. The version with DAC has a half-life measured in days and real human data. The version without it clears in hours and has no controlled human studies at all.
CJC-1295 is a long-acting GHRH analog, a modified fragment of growth hormone-releasing hormone built to stay in circulation for days instead of minutes. It does not deliver growth hormone. It stimulates the pituitary to release the body's own GH, the same mechanism sermorelin uses, but on a much longer clock. Two versions are sold under one name, and the difference between them is the single most important thing to get right before buying.
- CJC-1295 with DAC is a GHRH analog with an estimated half-life of 5.8 to 8.1 days [1]
- A single dose raised plasma GH 2 to 10-fold for 6 or more days and IGF-1 1.5 to 3-fold for 9 to 11 days [1]
- It does not flatten GH pulsatility. Pulse frequency and size held steady while basal GH rose 7.5-fold [2]
- The version without DAC is short-acting and largely uncharacterized in human research
- No CJC-1295 product is FDA-approved, and its only registered patient trial was terminated in 2006 [8]
- FDA has identified serious adverse events for CJC-1295, and it is prohibited in sport at all times [7][9]
What CJC-1295 Actually Is
CJC-1295 is a tetrasubstituted analog of the first 29 amino acids of GHRH, carrying an added group that bioconjugates to serum albumin in the bloodstream [3]. That albumin binding is the entire trick. It shields the peptide from the enzymes that clear ordinary GHRH within minutes, which is what stretches its action from minutes to days. The substitutions and the albumin tether are what separate it from sermorelin, which is the same GHRH fragment left unmodified.
With DAC Versus Without DAC
DAC stands for Drug Affinity Complex, the albumin-binding group. It is the difference between the two products sold as CJC-1295, and they behave nothing alike.
CJC-1295 with DAC is the version studied in humans. It carries the albumin tether, has a half-life of 5.8 to 8.1 days [1], and is dosed weekly or less often. CJC-1295 without DAC lacks that group, clears in a matter of hours, and is functionally closer to sermorelin in duration. It is frequently marketed as equivalent to Mod GRF 1-29, which is vendor nomenclature rather than established terminology.
There is almost none. The version without DAC has no controlled human trials and remains uncharacterized in the peer-reviewed literature. When a product is simply labeled CJC-1295, the form is often left unstated. Confirm which one a prescriber is dispensing, because the dosing schedule and everything known about the drug depend on that answer.
| CJC-1295 with DAC | CJC-1295 without DAC | |
|---|---|---|
| Albumin-binding group | Present | Absent |
| Half-life | 5.8 to 8.1 days [1] | Hours, closer to sermorelin |
| Typical dosing | Weekly or less often | Several times per week |
| Human research base | Published human studies [1][2] | None controlled |
What the Human Evidence Shows
In healthy adults, a single subcutaneous dose of CJC-1295 with DAC produced dose-dependent increases in mean plasma GH of 2 to 10-fold that lasted 6 days or more, and increases in IGF-1 of 1.5 to 3-fold that lasted 9 to 11 days [1]. With repeated weekly dosing, mean IGF-1 stayed above baseline for up to 28 days [1]. Those are large and sustained effects, and they are the reason the peptide is dosed so infrequently.
The evidence base is narrow. Two published studies in healthy volunteers describe what the drug does to GH and IGF-1 [1][2]. Neither measured body composition, strength, or the long-term outcomes people buy it for. There is no published trial of CJC-1295 for muscle, fat loss, or aging.
The Pulsatility Claim, Corrected
A common warning is that CJC-1295 flattens natural GH pulsatility. The study designed to test that found the opposite of what the warning implies. One week after dosing, GH pulse frequency and magnitude were unchanged, while basal GH rose 7.5-fold, mean GH rose 46%, and IGF-1 rose 45% [2].
Pulses continue at their normal rhythm and size. What rises is the trough between them, the baseline GH level that no longer falls as low. Whether chronically elevated basal GH matters over years has not been studied in humans. That is a real open question, and a different one from the pulsatility myth.
Why It Is Paired With Ipamorelin
CJC-1295 is rarely run alone. It is almost always stacked with ipamorelin, a selective secretagogue that acts on the ghrelin receptor rather than the GHRH receptor [5]. The reasoning is that two pathways converging on the same pituitary cells produce more GH than either alone.
That principle is measured, not theoretical. In healthy people, GH area under the curve was 686 for GHRH alone, 1787 for a secretagogue alone, and 4111 for the two together, well above the sum of the parts [6]. The study used GHRP-6 rather than ipamorelin, so the exact magnitude for a CJC-1295 and ipamorelin stack is an extrapolation. The direction of the effect is sound. The multiplier printed on vendor pages is not.
How It Is Dosed in Practice
Because CJC-1295 with DAC lasts for days, it is dosed on a weekly or twice-weekly schedule rather than nightly [1]. That is its main practical draw over sermorelin, which has to be injected every night to track the natural GH pulse [4]. Fewer injections is easier to sustain across the 6-month minimum any GH-axis protocol needs before outcomes can be judged.
The specific dose belongs to a prescriber working from your labs, not a stacking chart. What matters more than the number is that a baseline IGF-1 is drawn before the first injection and retested at 90 days, the point at which the IGF-1 response is expected to plateau. Without those two numbers there is no way to tell whether the dose is working or overshooting.
Safety and Regulatory Standing
No CJC-1295 product has ever been FDA-approved. It is dispensed only as a compounded preparation, and it carries regulatory signals rarely mentioned at point of sale.
FDA states it has identified serious adverse events for CJC-1295, including increased heart rate and systemic vasodilatory reaction, and that available clinical data are limited [7]. The only registered patient trial, a Phase 2 study in HIV-associated visceral obesity, is recorded as terminated in 2006 with no reason stated in the registry [8].
CJC-1295 is also named on the 2026 WADA Prohibited List under section S2.2.4, prohibited at all times in and out of competition [9]. Anyone subject to anti-doping testing should treat it as off the table.
The Honest Verdict
CJC-1295 with DAC is the version with actual human data behind it, and that data is thin: two studies describe its effect on GH and IGF-1, and nothing tests the outcomes people want from it. The convenience of weekly dosing is real. So is the FDA adverse event statement and the terminated trial. The no-DAC version sold under the same name has almost no evidence behind it at all.
If you pursue it, the discipline is the same as for any GH-axis therapy. Draw a baseline IGF-1 first. Confirm which form a licensed prescriber is dispensing. Retest IGF-1 at 90 days and treat a result above the age-adjusted range as a reason to lower the dose. A program that ships this peptide without a baseline draw has skipped the one step that makes the response measurable.
CJC-1295 with DAC raises IGF-1 for days at a time, which makes a starting number and a 90-day retest more useful, not less. SystemLabs tests IGF-1 before prescribing and formulates CJC-1295 and ipamorelin on clinical indication, so the protocol is built from your labs rather than a fixed template.
Frequently Asked Questions
What is the difference between CJC-1295 with and without DAC?
DAC, the Drug Affinity Complex, is the group that binds the peptide to serum albumin and gives it a half-life of 5.8 to 8.1 days [1]. The version with DAC is dosed weekly and is the one studied in humans. The version without DAC lacks that group, clears in hours, and is functionally closer to sermorelin. It is often sold as equivalent to Mod GRF 1-29, which is vendor nomenclature, and it has no controlled human studies behind it.
How long does CJC-1295 stay in your system?
CJC-1295 with DAC has an estimated half-life of 5.8 to 8.1 days [1]. Its effects outlast that: a single dose raised plasma GH 2 to 10-fold for 6 or more days 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 [1]. The version without DAC clears in hours.
Does CJC-1295 stop natural GH pulsatility?
No. The study built to test this found GH pulse frequency and magnitude unchanged one week after dosing, while basal GH rose 7.5-fold, mean GH rose 46%, and IGF-1 rose 45% [2]. Pulses persist at normal size and rhythm; the trough between them rises. Whether sustained basal elevation matters over years has not been studied in humans.
Is CJC-1295 FDA approved?
No. No CJC-1295 product has ever been FDA-approved, and it is dispensed only as a compounded preparation. FDA has identified serious adverse events for it, including increased heart rate and systemic vasodilatory reaction, and describes available clinical data as limited [7]. Its only registered patient trial was terminated in 2006 [8].
Is CJC-1295 better than sermorelin?
They are both GHRH analogs, and the practical difference is duration. CJC-1295 with DAC lasts 5.8 to 8.1 days and allows weekly dosing [1], while sermorelin clears in about 4 minutes and mirrors the natural nightly GH pulse [4]. No head-to-head trial has compared them. CJC-1295 buys dosing convenience against an FDA adverse event statement and a sustained basal GH rise whose long-term effect is unstudied.
Why is CJC-1295 usually combined with ipamorelin?
Because the two act on different receptors, and stimulating both produces more GH than either alone. CJC-1295 works through the GHRH receptor and ipamorelin through the ghrelin receptor [5]. In humans, a GHRH analog plus a secretagogue gave a GH response well above the sum of each separately [6], though that study used GHRP-6 rather than ipamorelin, so the exact size of the effect for this pairing is an estimate.
References
- 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/
- 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/
- 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/
- Ipamorelin, the first selective growth hormone secretagogue European Journal of Endocrinology, 1998. PMID: 9849822. https://pubmed.ncbi.nlm.nih.gov/9849822/
- Growth hormone (GH) secretion in active acromegaly after the combined administration of GH-releasing hormone and GH-releasing peptide-6 Journal of Clinical Endocrinology & Metabolism, 1994. PMID: 8045963. https://pubmed.ncbi.nlm.nih.gov/8045963/
- 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
- A multicenter, randomized, placebo-controlled, double-blind, phase 2 study to evaluate the efficacy and safety of CJC-1295 administered for 12 weeks in HIV infected patients with HIV associated visceral obesity ClinicalTrials.gov, 2006. NCT00267527, terminated. https://clinicaltrials.gov/study/NCT00267527
- 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
