The short version: ipamorelin acts on the ghrelin receptor and is short-acting. CJC-1295 acts on the GHRH receptor and, in its original "with DAC" form, binds albumin and lasts for days. Both reached human studies, both were dropped from development, and both are prohibited in sport by name.
Ipamorelin
Five residues, three of them non-standard. Made at Novo Nordisk in the 1990s and described as the first selective growth hormone secretagogue.1
CJC-1295
The first 29 residues of GHRH with four substitutions, plus a lysine that bonds to albumin after injection. Developed by ConjuChem.5
Side by side
| Point | Ipamorelin | CJC-1295 (with DAC) |
|---|---|---|
| Class | Growth hormone secretagogue, ghrelin-receptor agonist | GHRH analogue |
| Receptor | Ghrelin receptor (GHS-R1a) | GHRH receptor |
| Developer | Novo Nordisk | ConjuChem |
| Length | 5 residues | 30 residues |
| Avg mass | 711.9 g/mol | 3647.3 g/mol |
| CAS | 170851-70-4 | 446262-90-4 |
| Half-life in people | Short; modelled with growth hormone response in a 1999 volunteer study2 | About 6–8 days6 |
| Human studies | Volunteer pharmacokinetics; phase 2 trial in postoperative ileus, no benefit2,3 | Two studies in healthy adults, 2006; phase 2 halted the same year6,7 |
| Development | Discontinued after 2014 | Stopped in 2006 |
| Licensed | Nowhere | Nowhere |
| WADA | S2.2.4 · GH secretagogue | S2.2.4 · GHRH analogue |
Two receptors, one hormone
Growth hormone is released from somatotroph cells in the pituitary. Those cells respond to two separate signals: growth hormone-releasing hormone, through the GHRH receptor, and ghrelin, through the ghrelin receptor. CJC-1295 copies the first signal. Ipamorelin copies the second.1,5
That difference is why the two names often appear together. We found no published study of ipamorelin combined with CJC-1295 specifically, so any claim about the pair rests on the two compounds studied separately.
What was measured for each
| Area | Ipamorelin | CJC-1295 |
|---|---|---|
| Selectivity | Growth hormone release without the rise in ACTH and cortisol seen with older peptides, in pigs and rat pituitary cells1 | Not a main question |
| Duration | Blood levels and growth hormone response modelled together in volunteers2 | Growth hormone 2–10 times baseline for 6 days or more; IGF-1 1.5–3 times baseline for 9–11 days after one injection6 |
| Pulses | Not studied | Growth hormone kept its normal pulses under continuous stimulation7 |
| Clinical use | Gut recovery after bowel surgery: no benefit over placebo3 | No efficacy trial completed |
| Animal work | Longitudinal bone growth in young rats4 | Albumin binding and half-life in rats5 |
Which CJC-1295?
Two different peptides are sold under the CJC-1295 name. The original, "with DAC", has the albumin-binding lysine and lasts for days. "Without DAC", also called modified GRF (1–29), lacks it and is short-acting. Doping-control reviews note that papers and products often confuse the two.8
| With DAC | Without DAC | |
|---|---|---|
| Length | 30 residues | 29 residues |
| Avg mass | 3647.3 g/mol | 3367.9 g/mol |
| Binds albumin | Yes | No |
| Human data | Two 2006 studies | None of its own |
The two differ by about 280 g/mol, so the mass spectrum on a lot certificate tells them apart at once. Peptidarium sells the with-DAC form; its certificate shows the expected mass of 3647.3.
Common questions
What is the difference between ipamorelin and CJC-1295?
They act on different receptors. Ipamorelin is a ghrelin-receptor agonist; CJC-1295 is an analogue of growth hormone-releasing hormone. CJC-1295 with DAC also lasts far longer, about 6 to 8 days in people.
Why are ipamorelin and CJC-1295 mentioned together?
Because they reach the same cells through two different receptors. No published study has tested the two together, as far as we found.
Is CJC-1295 with DAC the same as without DAC?
No. Without DAC is modified GRF (1–29), the same 29 residues without the albumin-binding lysine. It is short-acting and about 280 g/mol lighter.
Were they tested in people?
Yes, both, in small studies. Ipamorelin had a pharmacokinetic study and a phase 2 trial that showed no benefit. CJC-1295 had two 2006 studies in healthy adults before development stopped.
Are ipamorelin and CJC-1295 banned in sport?
Yes. Both are named in WADA class S2.2.4 and are prohibited at all times.
References
- Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552–561. PMID 9849822
- Gobburu JV, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999;16(9):1412–1416. PMID 10496658
- Beck DE, Sweeney WB, McCarter MD. 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;29(12):1527–1534. PMID 25331030
- Johansen PB, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999;9(2):106–113. PMID 10373343
- Jetté L, et al. 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;146(7):3052–3058. PMID 15817669
- Teichman SL, 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;91(3):799–805. 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;91(12):4792–4797. PMID 17018654
- Memdouh S, et al. [Review of GHRH analogues in doping control, noting the DAC and no-DAC confusion]. Drug Test Anal. 2021;13(11–12):1871–1887. PMID 34665524
- World Anti-Doping Agency. The 2026 Prohibited List, class S2.2.4. wada-ama.org
Peptidarium Library. Ipamorelin vs CJC-1295 (comparison 03), 2 November 2026. peptidarium.com/compare/ipamorelin-vs-cjc-1295