CJC-1295: mechanism, DAC vs no-DAC, and the evidence

Last updated 2026-07-26

What is CJC-1295 and how does it work?

CJC-1295 is a synthetic peptide built to mimic growth hormone releasing hormone (GHRH), the 44-amino-acid hormone your hypothalamus normally sends to the pituitary gland to trigger growth hormone (GH) release. The name isn't marketing flavor text. It stands for a specific modified sequence: a 29-amino-acid GHRH fragment (matching the first 29 residues of native GHRH, which is the biologically active core) with four amino acid substitutions designed to resist enzymatic breakdown ^[1]. Those substitutions matter because native GHRH gets chewed up fast in the bloodstream by an enzyme called dipeptidyl peptidase-4 (DPP-4) and has a plasma half-life measured in single-digit minutes. CJC-1295's modified backbone resists that degradation, which is the whole reason it exists as a research tool instead of researchers just using native GHRH(1-29), also known as sermorelin. Mechanistically, CJC-1295 binds the GHRH receptor on somatotroph cells in the anterior pituitary. That binding activates a cyclic AMP signaling cascade that triggers the pituitary to release stored GH in a pulse. It does not add GH to your body directly. It stimulates your own pituitary to release more of its own GH than it otherwise would. That distinction is why people categorize it as a GH secretagogue rather than a GH replacement product like recombinant human growth hormone (rhGH) ^[2]. The original peptide development work, including the DAC modification described below, comes out of research published by Teichman et al. in the Journal of Clinical Endocrinology & Metabolism, which tested a modified GRF(1-29) with drug affinity complex technology in healthy adults and measured GH and IGF-1 responses over repeated dosing ^[2].

What does 'DAC' mean and how is it different from no-DAC?

DAC stands for Drug Affinity Complex, a chemical modification (a maleimide group covalently linked to the peptide) that lets the molecule bind reversibly to albumin, the most abundant protein floating around in blood plasma ^[2]. Once CJC-1295 is attached to albumin, it gets protected from enzymatic destruction and cleared much more slowly by the kidneys. The practical result: CJC-1295 with DAC has an elimination half-life reported at roughly 6 to 8 days in the Teichman study, compared to a half-life of about 30 minutes for the unmodified fragment, sometimes labeled CJC-1295 no-DAC or by its more accurate chemical name, Mod GRF (1-29) ^[2]. That's not a small difference. It's the difference between a peptide that needs dosing multiple times a day and one that could theoretically be dosed once a week and still keep circulating. Here's the tradeoff nobody in forum threads explains well. DAC's long half-life means it keeps low-level GHRH receptor stimulation going continuously, which in the Teichman trial produced sustained elevations in GH and IGF-1 over the full one to two week dosing interval studied, without dropping back to baseline between doses. No-DAC, because it clears in around 30 minutes, produces a sharp, short pulse of GHRH receptor activity that mimics the body's natural pulsatile GHRH release pattern more closely, then gets out of the way. Which one is 'better' depends entirely on what you're modeling. If the research question is about sustained, tonic elevation of the GH/IGF-1 axis, DAC is the tool that produces that pattern in the literature. If the research question is about preserving natural pulsatility, and pairing with a ghrelin-mimetic like ipamorelin timed to a specific pulse, no-DAC is the closer analogue to physiologic signaling. For a side by side breakdown of dosing frequency, cost per week, and half-life implications, see cjc 1295 dac vs no dac. | Feature | CJC-1295 with DAC | CJC-1295 no-DAC (Mod GRF 1-29) |

What does the actual clinical evidence show?

The most-cited primary source is the 2006 Teichman study in the Journal of Clinical Endocrinology & Metabolism, which tested modified GRF(1-29) with DAC in healthy adult volunteers ^[2]. The study reported that a single dose produced dose-dependent increases in GH lasting up to 6 days, and that multiple doses over a set interval produced sustained increases in IGF-1 of up to 1.5 to 3 times baseline, depending on dose, without evidence of pituitary desensitization over the treatment course studied. That is a real, peer-reviewed, PubMed-indexed trial, and it's worth reading directly rather than trusting a paraphrase ^[2]. But it's also worth being honest about its limits. It was a short-term pharmacodynamic study in a small number of healthy volunteers, not a long-term safety trial, not a trial in athletes seeking performance or body composition outcomes, and not a trial evaluating ipamorelin co-administration. Outside that study and the general GHRH-receptor pharmacology literature, there is very little controlled human research specifically on CJC-1295, and essentially none on CJC-1295 plus ipamorelin as a combined regimen. Almost everything written about specific dosing protocols, 'best' injection timing, or expected body composition changes traces back to bodybuilding forums and peptide vendor blogs, not to registered clinical trials. That's a meaningfully different evidence tier, and readers deserve to know which claims sit on which side of that line. For comparison, sermorelin (GRF 1-29 without the CJC modifications) has a longer clinical history and was FDA-approved for pediatric GH deficiency evaluation under the brand Geref before being discontinued from the market for commercial reasons, not safety findings ^[3]. CJC-1295 itself has never gone through FDA review for any indication.

Why is CJC-1295 usually paired with ipamorelin?

The rationale is mechanistic complementarity, not a proven combined clinical outcome. CJC-1295 works on the GHRH receptor pathway. Ipamorelin is a pentapeptide that works on a completely different receptor, the ghrelin/growth hormone secretagogue receptor (GHS-R), which triggers GH release through a separate signaling cascade and also suppresses somatostatin, the hormone that normally puts the brakes on GH release ^[4]. Because the two peptides hit different receptors that both converge on GH release, the theoretical argument is that combining them produces a larger or more reliable GH pulse than either alone, the same additive logic seen in earlier research combining GHRH analogues with GHRP-6 or GHRP-2 in academic GH-axis studies ^[5]. Ipamorelin specifically was developed and characterized as a selective GH secretagogue with minimal effect on cortisol, prolactin, or appetite compared to older GHRPs like GHRP-6, based on studies in the late 1990s ^[4]. That said, no registered controlled trial has tested CJC-1295 plus ipamorelin together and reported combined outcome data against either peptide alone or against placebo. The combination logic is borrowed from older GHRH-plus-GHRP research architecture, applied to newer, longer-acting molecules. It's a reasonable mechanistic hypothesis. It is not the same as saying the combination has been shown, in humans, to outperform either compound solo on any measured endpoint. Be skeptical of any source that states the combined effect as settled fact.

How is CJC-1295 typically dosed in research protocols?

Dosing described in the literature and in research-supplier documentation varies substantially by DAC status, and there's no single standardized regimen, because there's no approved product with an FDA label to standardize against. In the Teichman trial, single subcutaneous doses of DAC-modified GRF(1-29) ranged from 30 to 240 micrograms per kilogram of body weight, with repeated-dose data collected at intervals of one to two weeks across the study duration ^[2]. That's a research dosing schedule in a controlled trial setting, not a consumer protocol, and body-weight-scaled microgram-per-kilogram dosing does not map cleanly onto the flat microgram amounts commonly discussed in non-clinical contexts. No-DAC CJC-1295 (Mod GRF 1-29), because of its short half-life, is generally discussed in research materials as needing more frequent dosing, often multiple times per day or timed around specific windows, to produce repeated pulsatile stimulation rather than one sustained elevation. Reconstitution, storage stability, and injection technique all affect how consistent a research dose actually is peptide to peptide, and errors here are common. For the mechanics of reconstitution ratios and how to think about micrograms versus milliliters, see cjc 1295 dosage and, for DAC specifically where the long half-life changes the math, the cjc-1295 dac dosage calculator.

What are the known and theoretical side effects of CJC-1295?

Because there is no large-scale, long-term human safety trial specifically for CJC-1295, most of what's known comes from the short-term Teichman study, from general GH-axis pharmacology, and from adverse event patterns reported for GH secretagogues and rhGH more broadly. In the Teichman trial, reported effects included injection site reactions and flushing, along with expected on-target effects of elevated GH and IGF-1, without serious adverse events reported in that short study window ^[2]. Broader concerns raised in the GH secretagogue literature and by regulatory bodies include water retention, joint or soft tissue discomfort, elevated blood glucose from GH's anti-insulin effect, and theoretical long-term concerns about sustained IGF-1 elevation given IGF-1's role in cell growth signaling, though causal cancer risk in humans from peptide GH secretagogues specifically has not been established in controlled trials. The FDA has issued warnings about compounded GH secretagogue peptides broadly, including flagging that many are sold without agency review of safety, effectiveness, or manufacturing quality ^[6]. That regulatory gap is the single biggest practical safety issue: it's not necessarily that the molecule is inherently dangerous at studied doses, it's that unregulated production means you often don't actually know what's in the vial. For a full rundown of documented and theoretical adverse effects, see cjc 1295 side effects.

Is CJC-1295 legal to buy and use in the US?

CJC-1295 is not FDA-approved for any human medical use, and it is not a controlled substance under the federal Controlled Substances Act. It is sold in the US almost exclusively as a 'research chemical' labeled 'not for human consumption,' which is the legal fiction that lets peptide sellers operate outside FDA drug approval requirements while technically staying inside the law, as long as the buyer doesn't use it as a drug. The FDA has specifically named several GH-releasing peptides in warning letters and public communications about compounded drug safety concerns, and the agency's broader position is that peptides marketed as research chemicals but intended for human use are unapproved new drugs ^[6]. Buying, possessing, and self-administering it for personal use exists in a gray zone that regulators have not aggressively prosecuted for individuals, but that is a description of enforcement patterns, not a legal endorsement. Quality control is the real-world risk. Because these products bypass FDA manufacturing oversight, purity, dosing accuracy, and sterility vary a lot between suppliers, and independent testing of gray-market peptides has repeatedly found products under-dosed, over-dosed, or contaminated relative to their labels. That's exactly why sourcing quality matters more here than for almost any FDA-regulated product; see cjc 1295 for sale for what provider-reviewed sourcing looks like in practice. CJC-1295 Co's editorial position throughout this site is provider-reviewed sourcing information, pointing readers toward pharmacy-fulfilled options rather than unverified gray-market vendors, without CJC-1295 Co itself compounding, manufacturing, or dispensing anything.

How does CJC-1295 compare to other GH-axis peptides?

CJC-1295 sits in a specific slot in the GH secretagogue landscape: it's a long-acting or short-acting GHRH analogue, depending on DAC status, distinct from ghrelin-mimetic GHRPs (like ipamorelin, GHRP-2, GHRP-6, hexarelin) and distinct from tesamorelin, which is actually FDA-approved. Tesamorelin is the one GHRH analogue with real regulatory standing in the US: it's approved specifically for reduction of excess abdominal fat in HIV-associated lipodystrophy, under the brand Egrifta, based on Phase 3 trial data submitted to the FDA . That approval is narrow (a specific condition, a specific population) but it means tesamorelin has gone through controlled trials and FDA safety review in a way CJC-1295 has not. Sermorelin, the unmodified GRF(1-29), had a prior FDA-approved history for diagnostic use in evaluating pediatric GH deficiency before being discontinued commercially ^[3]. It shares CJC-1295's short-half-life core sequence but lacks any of the stability modifications. | Peptide | Class | FDA status | Approx. half-life |

What should someone weigh before starting CJC-1295 research?

Start with what problem you're actually trying to model or answer, because that determines whether DAC or no-DAC even makes sense as a starting point. Sustained IGF-1 elevation over a week points toward DAC's pharmacokinetic profile. Pulsatile signaling that mirrors natural GHRH release, especially in combination protocols, points toward no-DAC. Second, take the evidence base seriously and proportionately. One well-designed pharmacodynamic trial in healthy adults ^[2] tells you a lot about GH and IGF-1 kinetics over roughly two weeks. It tells you very little about outcomes over months or years, about combination effects with ipamorelin, or about long-term safety in populations with existing metabolic conditions. Third, sourcing quality is not a minor detail here, it's arguably the dominant risk factor, given the FDA's stated concerns about unapproved, non-reviewed peptide products ^[6]. A peptide that's underdosed does nothing. A peptide that's contaminated or mislabeled can do real harm, independent of whatever CJC-1295 itself does at a correct dose. Fourth, know your baseline. GH and IGF-1 elevation intersect with blood glucose regulation, thyroid function, and existing conditions like diabetes or a history of hormone-sensitive cancers in ways that matter clinically, which is a conversation for a physician, not a forum thread.

Frequently asked questions

What is CJC-1295 used for?

In research settings, CJC-1295 is used to study stimulation of endogenous growth hormone release via the GHRH receptor pathway. It has no FDA-approved human use. Most consumer interest centers on studying its effects on GH pulsatility and IGF-1 levels, often alongside ipamorelin, though that combination hasn't been tested in controlled human trials.

What is the difference between CJC-1295 with DAC and without DAC?

DAC (Drug Affinity Complex) lets CJC-1295 bind reversibly to blood albumin, extending its half-life from about 30 minutes (no-DAC) to roughly 6-8 days (DAC), based on the Teichman et al. 2006 study in the Journal of Clinical Endocrinology & Metabolism. DAC gives sustained GH/IGF-1 elevation; no-DAC gives a sharp, short pulse closer to natural GHRH signaling.

Does CJC-1295 actually increase growth hormone levels?

In the Teichman et al. trial, CJC-1295 with DAC produced dose-dependent GH increases and sustained IGF-1 elevations of roughly 1.5 to 3 times baseline in healthy adult volunteers over a multi-dose study period. That's the strongest human evidence available; it's a short controlled study, not long-term outcome data.

Is CJC-1295 legal in the United States?

It's not FDA-approved for human use and not a scheduled controlled substance, so it exists in a legal gray zone sold as a 'research chemical not for human consumption.' The FDA has raised broader concerns about unapproved peptide products sold this way, including quality and safety oversight gaps.

Why is CJC-1295 combined with ipamorelin?

CJC-1295 activates the GHRH receptor while ipamorelin activates the separate ghrelin/GHS receptor and suppresses somatostatin, so combining them targets two different points in the GH release pathway. This is a mechanistic rationale borrowed from older GHRH-plus-GHRP research, not a combination that's been proven superior in a controlled human trial.

How long does CJC-1295 stay in your system?

CJC-1295 with DAC has a reported elimination half-life of about 6-8 days due to albumin binding. CJC-1295 no-DAC (Mod GRF 1-29) has a much shorter half-life of roughly 30 minutes, per the pharmacokinetic data in Teichman et al., 2006, published in the Journal of Clinical Endocrinology & Metabolism.

What's the difference between CJC-1295 and sermorelin?

Sermorelin is the unmodified GHRH(1-29) fragment with a half-life of only minutes; it previously had FDA approval for pediatric GH deficiency diagnosis before being discontinued commercially. CJC-1295 is a chemically modified version of that same core sequence, engineered for much greater stability, with or without the DAC albumin-binding modification.

What's the difference between CJC-1295 and tesamorelin?

Tesamorelin is a different GHRH analogue that actually holds FDA approval, specifically for reducing excess abdominal fat in HIV-associated lipodystrophy under the brand Egrifta, based on Phase 3 trial data. CJC-1295 has no FDA approval for any indication and is sold only as a research compound.

What are the side effects of CJC-1295?

The short-term Teichman trial reported injection site reactions and flushing without serious adverse events. Broader theoretical concerns tied to elevated GH/IGF-1 include water retention, joint discomfort, and impaired glucose tolerance, though long-term controlled safety data specific to CJC-1295 doesn't exist.

How is CJC-1295 dosed in studies?

In the Teichman trial, DAC-modified doses ranged from 30 to 240 micrograms per kilogram of body weight, given as single or repeated subcutaneous injections spaced one to two weeks apart. No standardized consumer dosing protocol exists because there's no FDA-approved product or label to base one on.

Can CJC-1295 be detected in a drug test?

Standard workplace or medical drug panels don't screen for GH secretagogue peptides like CJC-1295. Specialized anti-doping labs, such as those working with WADA-accredited testing, can detect GH-axis manipulation using specific assays, which is why CJC-1295 and similar peptides are prohibited under WADA's list of prohibited substances for competitive athletes.

Does CJC-1295 cause cancer?

No controlled human trial has established that CJC-1295 causes cancer. The theoretical concern is that sustained IGF-1 elevation could support growth of existing hormone-sensitive tumors, since IGF-1 is a cell growth signaling molecule, but causal cancer risk from CJC-1295 specifically hasn't been demonstrated in research.

Where can I find provider-reviewed CJC-1295 sourcing?

Because CJC-1295 is unregulated as a research chemical, purity and labeling accuracy vary widely between vendors. Look for provider-reviewed listings that name a fulfilling pharmacy partner and disclose testing practices rather than anonymous gray-market sellers; see our sourcing guide for what that verification should include.

Sources

1. National Center for Biotechnology Information (PubChem), CJC-1295 Compound Summary: CJC-1295 is a modified 29-amino-acid GHRH analogue engineered for resistance to enzymatic degradation
2. Teichman SL et al., Journal of Clinical Endocrinology & Metabolism, 2006: DAC-modified GRF(1-29) half-life, dosing range, and sustained GH/IGF-1 elevation data from the primary human trial
3. U.S. National Library of Medicine, DailyMed, Geref (sermorelin) prescribing information: Sermorelin (GRF 1-29) previously held FDA approval for pediatric GH deficiency evaluation before discontinuation
4. Raun K et al., European Journal of Endocrinology, 1998 (ipamorelin characterization): Ipamorelin acts on the ghrelin/GHS receptor and shows selective GH release with minimal cortisol and prolactin effects
5. PubMed, GHRH and GHRP combination studies on GH axis: Combining GHRH analogues with ghrelin-mimetic GHRPs has an established academic rationale for additive GH release
6. U.S. Food and Drug Administration, Egrifta (tesamorelin) approval information: Tesamorelin is FDA-approved specifically for reduction of excess abdominal fat in HIV-associated lipodystrophy