Sermorelin and CJC-1295 are analogs of growth-hormone-releasing hormone, while ipamorelin is a different kind of molecule, a ghrelin-receptor agonist, so the three reach the pituitary through two separate receptors. Their evidence differs just as much: sermorelin was an FDA-approved drug with a pediatric trial behind it, while CJC-1295 and ipamorelin have early human studies that measured hormone release and have never been approved for anything.
We found no published trial that compares the three head to head. The comparison below sets their records side by side and names the model each finding came from.
At a glance
| Ipamorelin | Sermorelin | CJC-1295 | |
|---|---|---|---|
| What it is | Synthetic five-amino-acid peptide | The first 29 amino acids of human growth-hormone-releasing hormone (GHRH) | A modified GHRH(1-29) built to bind albumin in the blood |
| Receptor | Ghrelin (growth hormone secretagogue) receptor | GHRH receptor | GHRH receptor |
| Origin | Novo Nordisk, described in 1998 | Marketed in the US as Geref by EMD Serono | ConjuChem, Montreal, described in 2005 |
| Human evidence | A pharmacokinetic study in healthy men; a phase 2 trial in 114 surgery patients that found no significant benefit | A one-year open-label study in 110 children with growth hormone deficiency; small studies in older adults | Two randomized studies in healthy adults measuring growth hormone and IGF-1 |
| FDA approval | None | Approved in 1990 and 1997; discontinued in 2008 | None |
| Compounding review | Advisory committee voted 0 to 12 against, October 2024 | Not on the FDA's nominated-substance category list | Advisory committee voted against every form, December 2024 |
| Sport | Prohibited (WADA S2) | Prohibited (WADA S2) | Prohibited (WADA S2) |
Two receptors, three molecules
Sermorelin is the simplest of the three. A 1999 review in BioDrugs (Prakash and Goa) describes it as a 29-amino-acid analog of human GHRH and the shortest synthetic peptide with the hormone's full biological activity.
CJC-1295 starts from the same 29 residues. Researchers at ConjuChem (Jetté and colleagues, Endocrinology, 2005) changed four of them and added a reactive group designed to attach the peptide to albumin, the most abundant protein in blood, to keep it in circulation longer. In rats, they reported that the compound was still detectable in plasma beyond 72 hours. The name is also used for a version without the albumin-binding group, usually written "CJC-1295 without DAC" (for drug affinity complex). The FDA's December 2024 review listed the two forms separately.
Ipamorelin is unrelated to GHRH. Raun and colleagues at Novo Nordisk (European Journal of Endocrinology, 1998) described it as a pentapeptide that released growth hormone from rat pituitary cells in culture and in rats and swine, acting through the same receptor as an earlier compound, GHRP-6. That receptor is now known as the ghrelin receptor. What they highlighted was selectivity: in swine, the comparison compounds raised ACTH and cortisol, and ipamorelin did not raise them significantly more than GHRH did.
The human record
Sermorelin has the deepest record because it went through an approval. In the Geref International Study Group trial (Thorner and colleagues, Journal of Clinical Endocrinology and Metabolism, 1996), 110 previously untreated children with growth hormone deficiency received it for up to a year in a multicenter, open-label study. Among the 86 children eligible for the efficacy analysis, mean height velocity rose from 4.1 centimeters a year at baseline to 7.2 at twelve months. In adults the work is much smaller. Corpas and colleagues (same journal, 1992) gave it to 10 healthy older men for two weeks and reported that growth hormone and IGF-1 rose toward the levels measured in 9 young men. That is a hormone measurement over 14 days, not a health outcome.
CJC-1295 was tested in healthy adults in two randomized, placebo-controlled, double-blind studies (Teichman and colleagues, same journal, 2006). After a single administration, mean plasma growth hormone rose 2 to 10 fold for six days or more and mean IGF-1 rose 1.5 to 3 fold for 9 to 11 days, with an estimated half-life of roughly 6 to 8 days and no serious adverse reactions reported. A follow-up in healthy men aged 20 to 40 (Ionescu and Frohman, same journal, 2006) reported that the pulsing pattern of growth hormone release was preserved while baseline levels rose. Both studies measured hormone levels. Neither tested a clinical benefit.
The program then stopped. In July 2006 ConjuChem halted a phase 2 trial in people with HIV-associated lipodystrophy after a participant died, and said at the time that the cause and any relationship to the drug were under investigation. We found no later published efficacy trial.
Ipamorelin has two published human studies of note. Gobburu and colleagues (Pharmaceutical Research, 1999) infused it in healthy men, eight at each of five levels, and described a single burst of growth hormone peaking at about 40 minutes, with a half-life for the peptide of about two hours. The larger study was not about growth hormone at all: because ghrelin-receptor agonists affect gut motility, ipamorelin was tested for postoperative bowel recovery. In that phase 2 trial (Beck and colleagues, International Journal of Colorectal Disease, 2014), 114 bowel-resection patients were analyzed, and the authors reported no significant differences between ipamorelin and placebo on the main or secondary efficacy measures.
What is missing
Sermorelin's strongest data are in children who lacked growth hormone. For CJC-1295 and ipamorelin, the published human work measures growth hormone or IGF-1 in the blood, apart from the bowel-recovery trial that did not show a benefit. We found no published randomized trial of either with a clinical outcome such as strength, function or body composition as its endpoint. We also found no published randomized trial of the two combined, a pairing that is widely discussed online. The reasoning behind it is that they act on different receptors, which is a hypothesis about mechanism, not a result. Our piece on reading a peptide study explains why a change in a blood marker and a clinical outcome are different kinds of evidence.
Regulatory status
Sermorelin is the only one of the three that was ever an approved drug. According to a 2013 Federal Register notice, Geref was approved on December 28, 1990 as a test of the pituitary's ability to secrete growth hormone, and on September 26, 1997 for idiopathic growth hormone deficiency in children with growth failure. EMD Serono told the FDA in 2008 that it was discontinuing both, and the approvals were withdrawn in 2009. The FDA later determined that the products were not withdrawn from sale for reasons of safety or effectiveness. The FDA's drug database lists both Geref applications as discontinued and shows no other sermorelin product. Material sold under the name by research suppliers is not Geref.
CJC-1295 and ipamorelin have never been approved. Both were nominated for the list of bulk substances that pharmacies may compound, and both were reviewed by the FDA's Pharmacy Compounding Advisory Committee. On October 29, 2024 the committee voted 0 to 12, with one abstention, against adding ipamorelin. On December 4, 2024 it voted against every form of CJC-1295, unanimously for four of the five. The FDA's safety summary for CJC-1295 cites serious adverse events, including increased heart rate, and says the available clinical data are limited. For ipamorelin, it notes a published study linking intravenous use to serious adverse events, including death. Neither peptide was among those the committee reconsidered in July 2026.
The growth-hormone-releasing drug that does hold an approval today is tesamorelin, covered in our review of the growth-hormone axis.
Sport
All three are prohibited at all times under section S2 of the World Anti-Doping Agency's 2026 Prohibited List. The list names CJC-1295 and sermorelin as examples of GHRH analogs and ipamorelin as an example of a growth hormone secretagogue.
Frequently asked questions
Is sermorelin FDA-approved?
It was. Geref, a sermorelin product, was approved in 1990 and 1997 and discontinued by its maker in 2008. The FDA found the withdrawal was not for safety or effectiveness reasons.
What is the difference between CJC-1295 and sermorelin?
Both are based on the first 29 amino acids of GHRH. CJC-1295 has four substitutions and, in its original form, a group that binds albumin, which the developers reported kept it in circulation far longer.
Is ipamorelin a GHRH analog?
No. It acts at the ghrelin receptor, a separate route to growth hormone release. Sermorelin and CJC-1295 act at the GHRH receptor.
Has the CJC-1295 and ipamorelin combination been tested in a trial?
We found no published randomized human trial of the combination.
Sources:
- Prakash and Goa, BioDrugs, 1999 (review of sermorelin)
- Thorner et al., J Clin Endocrinol Metab, 1996 (Geref International Study Group, 110 children)
- Corpas et al., J Clin Endocrinol Metab, 1992 (older and young men)
- Jetté et al., Endocrinology, 2005 (identification of CJC-1295, rats)
- Teichman et al., J Clin Endocrinol Metab, 2006 (CJC-1295 in healthy adults)
- Ionescu and Frohman, J Clin Endocrinol Metab, 2006 (growth hormone pulsatility)
- Dominikowski et al., Front Endocrinol, 2026 (review of peptides acting on the growth hormone axis, including both CJC-1295 forms)
- aidsmap, "Lipodystrophy study halted after patient death," July 2006
- Raun et al., Eur J Endocrinol, 1998 (ipamorelin in rat cells, rats and swine)
- Gobburu et al., Pharm Res, 1999 (ipamorelin in healthy volunteers)
- Beck et al., Int J Colorectal Dis, 2014 (phase 2, postoperative ileus)
- FDA, determination that Geref was not withdrawn for reasons of safety or effectiveness, Federal Register, March 4, 2013
- Drugs@FDA, Geref (sermorelin acetate), NDA 020443
- FDA, summary minutes, Pharmacy Compounding Advisory Committee, October 29, 2024 (ipamorelin)
- FDA, summary minutes, Pharmacy Compounding Advisory Committee, December 4, 2024 (CJC-1295)
- FDA, Certain bulk drug substances for use in compounding that may present significant safety risks
- FDA, Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (category list, updated May 14, 2026)
- FDA, July 23 to 24, 2026 meeting of the Pharmacy Compounding Advisory Committee
- WADA 2026 Prohibited List, as published in the Dutch treaty series (S2)
Aside from the discontinued Geref products, no compound discussed in this review has been FDA-approved. Nothing above is dosing guidance or a treatment claim. Research use only.
For research use only · Not for human or veterinary use · No research compound discussed here is FDA-approved for any indication