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Research Memos

CJC-1295 with DAC vs ipamorelin

CJC-1295 with a drug affinity complex (DAC) binds albumin, a blood protein, and stimulates the receptor for growth hormone-releasing hormone (GHRH). Small healthy-adult studies found prolonged growth hormone (GH) and insulin-like growth factor 1 (IGF-1) increases with this form. Ipamorelin acts through the ghrelin-receptor system; a human infusion study measured a shorter peptide half-life, and its bowel-surgery trial left clinical benefit uncertain. No cited trial establishes which improves muscle growth, recovery or longevity.

Research reviewed October 15, 2026. Educational information only.

The DAC distinction changes this comparison

CJC-1295 with DAC is a modified growth hormone-releasing hormone (GHRH) analogue. DAC is the added drug affinity complex that allows the molecule to attach to albumin, an abundant blood protein, and prolong its presence. The healthy-adult clinical reports concern this albumin-binding preparation. A product described as “CJC-1295 no DAC” or modified GRF(1–29) lacks that attachment system; it does not inherit the long-acting trial’s exposure results.

Ipamorelin is a synthetic five-residue peptide that activates the ghrelin-receptor system. GHRH and ghrelin provide different inputs to cells involved in growth hormone release. Their ability to raise the same downstream hormone explains why the compounds are often discussed together, but neither receptor biology nor co-marketing establishes a clinical benefit from combining them.

The main differences

Which receptor and molecular form was studied?

The name CJC-1295 needs its DAC qualifier because the long-acting trials used an albumin-binding preparation. Receptor identity describes how hormone release is stimulated, without demonstrating clinical superiority.

CJC-1295 with DAC

The studied CJC-1295 with DAC is a modified growth hormone-releasing hormone (GHRH) analogue that binds albumin, a blood protein, and stimulates the GHRH receptor. Modified GRF(1–29), often sold under a no-DAC name, is a different preparation and does not inherit the long-acting clinical results.

Sources

Ipamorelin

Ipamorelin is a five-residue synthetic peptide acting through the ghrelin-receptor system. Its original pharmacology used cells, rats and pigs, while subsequent human studies assessed exposure and postoperative gut recovery.

Sources

What did controlled human research actually show?

CJC-1295 studies measured growth hormone (GH) and insulin-like growth factor 1 (IGF-1) concentrations in healthy adults; ipamorelin’s clinical efficacy trial measured meal tolerance after bowel surgery. These results address different clinical questions.

CJC-1295 with DAC

Two placebo-controlled trials in healthy adults found that mean GH rose 2–10-fold for at least six days and IGF-1 rose 1.5–3-fold for nine to eleven days after a subcutaneous injection. They did not demonstrate improved physical performance or recovery.

Sources

Ipamorelin

Among 114 people in the main bowel-surgery analysis populations, median solid-meal tolerance time was 25.3 hours with intravenous ipamorelin and 32.6 hours with placebo. The earlier numerical time did not establish benefit (P=0.15).

Sources

What do the human half-life estimates describe?

A peptide half-life concerns disappearance of that measured peptide. It differs from a GH peak or an IGF-1 response, and the cited studies used different administration routes.

CJC-1295 with DAC

After subcutaneous albumin-binding CJC-1295, the estimated peptide half-life was 5.8–8.1 days. This estimate cannot be assigned to a no-DAC product or converted into a duration of muscle growth or healing.

Sources

Ipamorelin

Healthy men receiving short intravenous infusions had an estimated ipamorelin terminal half-life of about two hours. Growth hormone peaked separately around 0.67 hours. The study does not supply the exposure of every subcutaneous formulation.

Sources

Does hormone release establish a better muscle-growth or anti-aging effect?

None of the cited trials randomized people between these compounds for a shared functional outcome. Differences in hormone levels cannot supply that missing comparison.

CJC-1295 with DAC

Growth hormone (GH) pulses persisted one week after administration, while concentrations between pulses rose 7.5-fold. The physiology study did not establish improved strength, recovery or lifespan, and persistent pulses did not mean unchanged total hormone exposure.

Sources

Ipamorelin

The human infusion study measured peptide concentrations and GH release; the postoperative trial studied gut recovery. Neither established sustained muscle growth, healthy-adult recovery or a longer lifespan.

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Can the available data establish which is safer?

Short healthy-volunteer trials, postoperative adverse events and animal hormone selectivity describe different risks. There is no direct randomized safety comparison in the cited sources.

CJC-1295 with DAC

FDA identifies limited clinical data, possible immune reactions and peptide-quality concerns, as well as reported increased heart rate and systemic vasodilation, a widening of blood vessels. The original trial’s absence of reported serious reactions cannot establish long-term safety.

Sources

Ipamorelin

Pig hormone selectivity does not establish human safety. FDA discusses quality and immune-reaction concerns and serious events, including deaths with uncertain drug attribution, in intravenous postoperative research. Safety information for some other injectable routes is missing.

Sources

What the long-acting CJC-1295 studies measured

Teichman and colleagues conducted two randomized double-blind placebo-controlled trials in healthy adults aged 21–61, with follow-up lasting 28 and 49 days. After a single subcutaneous injection, mean GH concentrations increased 2–10-fold for at least six days and IGF-1 increased 1.5–3-fold for nine to eleven days. IGF-1 is a growth-related protein whose production responds to GH. The original abstract does not supply participant totals, and the measured effects were hormone concentrations and peptide exposure.

A separate overnight study sampled healthy men every twenty minutes for twelve hours before and one week after CJC-1295. GH pulses remained detectable, while concentrations between pulses rose 7.5-fold (P<0.0001). Average GH increased 46% (P<0.01) and IGF-1 increased 45% (P<0.001); pulse frequency and magnitude were not established as changed. FDA’s source-specific review identifies twelve men. The persisting pulses coexisted with higher between-pulse and average hormone concentrations.

Neither experiment established improved strength, healing after injury or longer life. Preserved pulse timing cannot stand in for those outcomes, and an increase in IGF-1 is not itself a measure of how a person feels or functions.

Ipamorelin connects hormone measurements with a different clinical trial

In healthy men, Gobburu and colleagues measured ipamorelin and released GH after short intravenous infusions. The design used eight men at each of five exposure levels, without stating a total number of unique participants in the abstract. GH rose in one episode and peaked around 0.67 hours. This was a study of circulating peptide and hormone response, rather than a trial of muscle gain or recovery.

The subsequent postoperative trial asked a clinical question about the return of gut function after bowel resection. It enrolled 117 adults and included 114 in the main safety and efficacy populations. Median time to tolerate a standardized solid meal was 25.3 hours with intravenous ipamorelin and 32.6 hours with placebo. The earlier numerical time was too uncertain to establish a treatment effect (P=0.15), and the secondary analyses also did not establish differences. A possible effect remained unresolved; the finding does not prove identical outcomes.

That bowel-surgery result cannot be compared numerically with CJC-1295’s GH fold increase. The studies involved different participants, routes, follow-up periods and measurements. A head-to-head clinical ranking would require the compounds to be tested against the same outcome in comparable patients.

How long the peptides remained in blood

The CJC-1295 trials estimated a peptide half-life of 5.8–8.1 days after subcutaneous administration of the albumin-binding preparation. The human ipamorelin infusion study estimated a terminal half-life of about two hours after intravenous administration. These values describe how the measured administered peptides disappeared from blood under their respective study conditions.

Downstream hormone release follows its own time course. In the ipamorelin study, GH peaked before one hour even though the peptide’s terminal disappearance took longer. With CJC-1295, repeated exposure left mean IGF-1 above baseline for up to 28 days. Neither observation specifies the duration of a clinical benefit. The route difference also prevents treating the two half-lives as a direct comparison of subcutaneous products.

Short hormone studies leave important safety questions open

The CJC-1295 trial abstract reported no serious adverse reactions during its limited follow-up. FDA’s later assessment identifies limited clinical data and reports including increased heart rate and systemic vasodilation, a widening of blood vessels. The agency also identifies possible immune reactions and complexities in identifying peptide impurities. A short healthy-volunteer experiment cannot establish safety over years of sustained GH or IGF-1 elevation.

For ipamorelin, the often-cited selectivity experiment was conducted in cells and animals. In the pig comparisons, ACTH and cortisol responses were not established as higher than those with GHRH. ACTH signals the adrenal glands to release cortisol, a stress hormone. That observation does not establish a complete human safety advantage.

In the bowel-surgery trial, adverse events after treatment began were reported in 87.5% of ipamorelin recipients and 94.8% of placebo recipients. FDA’s detailed review also discusses two deaths in ipamorelin recipients with postoperative complications; whether the drug contributed was unclear. FDA identifies quality and immune-reaction concerns for ipamorelin acetate and missing information for some injectable routes. These sources do not support identifying either compound as the safer option for an untested use.

What the evidence can explain about the two compounds

The supported distinction is pharmacological: albumin-binding CJC-1295 produces prolonged hormone stimulation, while ipamorelin acts through a different receptor and has human intravenous exposure and postoperative gut-recovery data. Their literature does not establish a relative improvement in adult muscle mass, strength, recovery or longevity. Combining them introduces another intervention that these separate trials did not evaluate.

For the molecular distinction, read CJC-1295 with DAC and modified GRF(1–29), or the comparison of those preparations. The ipamorelin profile develops the animal selectivity result and human postoperative trial.

Frequently asked questions

Does this comparison include CJC-1295 without DAC?

The long-acting human findings concern albumin-binding CJC-1295 with DAC. The no-DAC name often refers to modified GRF(1–29), which must be assessed as its own preparation.

Do preserved GH pulses show normal overall exposure?

In the overnight CJC-1295 study, pulse frequency and magnitude were not established as changed, but between-pulse GH rose 7.5-fold and mean GH rose 46%. Pulse timing alone therefore does not describe total exposure or clinical safety.

Do the separate studies validate combining the peptides?

They studied individual preparations in different experiments. A shared downstream hormone and different receptor inputs do not establish the benefit or safety of a combined product.

Did ipamorelin prove ineffective after bowel surgery?

Patients tolerated a meal earlier numerically, but the small trial did not establish a treatment effect (P=0.15). The result leaves benefit uncertain rather than proving identical effects.

CJC-1295 with DAC — full profile · Selected studies

Ipamorelin — full profile · Selected studies

Compare other compounds · Explore the guide previews

References

  1. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. 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. The Journal of clinical endocrinology and metabolism. 2006;91(3):799–805. doi:10.1210/jc.2005-1536. PMID:16352683.

    Two placebo-controlled healthy-adult trials found sustained increases in GH and IGF-1 with albumin-binding CJC-1295. The estimated peptide half-life was 5.8–8.1 days; the trials measured hormone concentrations rather than recovery or physical performance.

  2. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. The Journal of clinical endocrinology and metabolism. 2006;91(12):4792–4797. doi:10.1210/jc.2006-1702. PMID:17018654.

    Overnight sampling in healthy men found that GH pulses persisted one week after CJC-1295. Concentrations between pulses rose 7.5-fold, mean GH rose 46% and IGF-1 rose 45%; pulse frequency and magnitude were not established as changed.

  3. Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue. European journal of endocrinology. 1998;139(5):552–561. doi:10.1530/eje.0.1390552. PMID:9849822.

    Ipamorelin released growth hormone in cells, rats and pigs. In pigs, responses of ACTH, a pituitary signal to the adrenal glands, and the stress hormone cortisol were not established as higher than responses to growth hormone-releasing hormone (GHRH). GHRP-2 and GHRP-6 raised those hormones under the tested conditions.

  4. Gobburu JV, Agersø H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharmaceutical research. 1999;16(9):1412–1416. doi:10.1023/a:1018955126402. PMID:10496658.

    Healthy men received short intravenous ipamorelin infusions. The peptide’s estimated terminal half-life was about two hours; released growth hormone peaked around 0.67 hours. The abstract gives eight men at each level without a unique total.

  5. Beck DE, Sweeney WB, McCarter MD, Ipamorelin 201 Study Group. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. International journal of colorectal disease. 2014;29(12):1527–1534. doi:10.1007/s00384-014-2030-8. PMID:25331030.

    After bowel resection, median time to tolerate a solid meal was 25.3 hours with intravenous ipamorelin and 32.6 hours with placebo. This favorable numerical difference did not establish benefit (P=0.15); 114 of 117 enrolled people formed the main analysis populations.

  6. U.S. Food and Drug Administration. December 4, 2024 Pharmacy Compounding Advisory Committee Meeting. CJC-1295-related bulk drug substances briefing document.

    The agency separates CJC-1295 forms with and without DAC, reconstructs the small healthy-adult studies and explains why hormone increases have not established clinical effectiveness for GH deficiency.

  7. U.S. Food and Drug Administration. October 29, 2024 Meeting of the Pharmacy Compounding Advisory Committee. Ipamorelin-related bulk drug substances briefing document.

    The agency reviews the uncertain postoperative efficacy comparison and safety events, including two deaths among ipamorelin recipients with postoperative complications. Drug causation was unclear; the report does not establish safety for other injectable routes.

  8. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Accessed October 15, 2026.

    FDA identifies immune-reaction and peptide-quality concerns for CJC-1295 and ipamorelin acetate. It also notes increased heart rate and systemic vasodilation with CJC-1295 and serious events in intravenous ipamorelin research, without establishing causation for every event.