CJC-1295 ipamorelin myths: what the research does not show
Hormonal, Growth Hormone & Body Composition Research
CJC-1295 and ipamorelin each have a few small human studies showing they raise growth hormone, but we found no published human study of the two together, and none that measured muscle, fat loss or ageing as an outcome. This page sorts the claims about the pairing into what was measured and what was assumed.
Findings
- In healthy adults, one administration of long-acting CJC-1295 raised mean growth hormone 2- to 10-fold for 6 days or more and IGF-1 1.5- to 3-fold (J Clin Endocrinol Metab, 2006).
- A second 2006 study found growth hormone kept its natural pulse pattern after CJC-1295, while trough levels rose 7.5-fold.
- Ipamorelin produced a single, short pulse of growth hormone in healthy male volunteers, with a half-life of about 2 hours (Pharm Res, 1999).
- The biggest gap: no published human trial of CJC-1295 combined with ipamorelin, and no trial of either that measured muscle or body fat.
View product →Myth: the CJC-1295 and ipamorelin combination is proven in humans
We found no published human study of the pair. The human data are separate: two 2006 CJC-1295 studies in healthy adults and a 1999 ipamorelin study in healthy men, all measuring hormone levels over days or hours. The reasoning behind the pairing is sound pharmacology, since the two act on different receptors. Sound reasoning is not the same as a tested result.
Myth: the CJC-1295 human studies describe the no-DAC version
They do not. The 2006 trials used CJC-1295 with DAC, a version built to bind albumin in the blood, which gave it an estimated half-life of 5.8 to 8.1 days. CJC-1295 without DAC, the form in many CJC-1295 + ipamorelin blends, lacks that albumin-binding part, so the multi-day figures from those trials do not describe it. Neither form is better or worse on this evidence. They are different molecules with different timing, and the published human numbers belong to the DAC form.
Myth: CJC-1295 keeps growth hormone completely natural
Partly true. In the second 2006 study, healthy young men kept the same number and size of growth hormone pulses after receiving CJC-1295 with DAC. But the baseline between pulses rose 7.5-fold, and mean growth hormone rose 46%. So the rhythm was preserved while the overall level was raised well above normal. “Pulsatile” is accurate; “unchanged” is not.
Myth: the pairing builds muscle and burns fat
No study of CJC-1295 or ipamorelin has measured that in people. The claim is borrowed from growth hormone itself. A 2007 systematic review of growth hormone in healthy older adults, a different compound, found about 2.1 kg more lean mass and 2.1 kg less fat, but higher rates of swelling, joint pain, carpal tunnel syndrome and breast tissue growth in men. The reviewers concluded growth hormone could not be recommended for anti-ageing. Even the parent hormone’s evidence is weaker than the marketing.
Myth: ipamorelin raises growth hormone with no other hormone effects
Partly true, in animals. In 1998 work in pigs, ipamorelin released growth hormone without the cortisol and ACTH rise seen with older peptides in its class, even far above the level needed to release growth hormone. That selectivity is why it is called the first selective growth hormone secretagogue. We found no long-term human data on its wider hormone effects.
Myth: ipamorelin has already succeeded in human trials
Not on the published record. In a 2014 phase 2 trial in 114 adults recovering from bowel surgery, ipamorelin was well tolerated, but time to the first tolerated meal, 25.3 hours against 32.6 hours on placebo, was not a significant difference. That was its only efficacy trial we found, and it was not in a fitness or ageing setting.
What CJC-1295 and ipamorelin cannot promise
The published human work shows these peptides raise growth hormone for a while. It stops there.
- They cannot promise more muscle or less fat; neither was measured.
- They cannot promise the combined effect people describe; the pair has not been studied together.
- They cannot promise that DAC trial figures apply to the no-DAC form.
- They cannot promise long-term safety; the human studies lasted weeks at most.
Where the evidence stands
Neither CJC-1295 nor ipamorelin is an approved medicine in Canada for any use. Both reached early human testing only. A 2026 sports medicine review covered both and described rigorous human safety data for unapproved peptides as scarce. They are supplied for laboratory research.
Vistara Labs supplies CJC-1295 + ipamorelin as a laboratory research material. The page above is about the published research, not a claim about our product.
Frequently asked questions
Has the CJC-1295 and ipamorelin combination been studied in humans?
We found no published human study of the two together. Each has been studied on its own in small groups of healthy volunteers, measuring growth hormone and IGF-1 levels.
What is the difference between CJC-1295 with DAC and without DAC?
The DAC version binds albumin in the blood, giving it an estimated half-life of 5.8 to 8.1 days in the 2006 human trials. The no-DAC version lacks that part, so those trial figures do not describe it.
Does ipamorelin raise cortisol?
In 1998 studies in pigs, ipamorelin did not raise cortisol or ACTH beyond the levels seen with growth hormone-releasing hormone. We found no long-term human data on this.
Sources: Teichman SL, Neale A, Lawrence B, et al. 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. J Clin Endocrinol Metab. 2006. PMID 16352683. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006. PMID 17018654. Gobburu JV, Agersø H, Jusko WJ, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999. PMID 10496658. Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. PMID 9849822. Beck DE, Sweeney WB, McCarter MD, et al. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. 2014. PMID 25331030. Liu H, Bravata DM, Olkin I, et al. Systematic review: the safety and efficacy of growth hormone in the healthy elderly. Ann Intern Med. 2007. PMID 17227934. Mendias CL, Awan TM. Safety and efficacy of approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance. Sports Med. 2026. PMID 41966639.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
References
The published human CJC-1295 trial used the long-acting DAC analogue, not the no-DAC form. Ipamorelin has its own human pharmacokinetic study. No trial of the two combined was identified.
- 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 adultsRandomised placebo-controlled trial in healthy adults — of the LONG-ACTING (DAC) CJC-1295 analogue, not the no-DAC form.
- Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteersHuman pharmacokinetic/pharmacodynamic study; five escalating infusion levels, eight healthy male subjects per level.
Links open the study record on PubMed so the source can be checked directly. Listing a study is not a claim that its findings apply to any other use, product or route of administration. Research use only.
