What are CJC-1295 and ipamorelin, and why are they two different molecules?
The phrase "CJC-1295 ipamorelin" names a pair, not a compound. CJC-1295 was built at ConjuChem in Montreal as a growth-hormone-releasing hormone (GHRH) fragment that would last longer than the native hormone: four amino acids were swapped to resist enzymatic cleavage, and a maleimide group was added on a thirtieth lysine so that the peptide binds covalently to cysteine 34 of serum albumin in plasma [7]. That linker is the "DAC", and it is why the human half-life came out at 5.8 to 8.1 days [1]. The molecule has its own page, CJC-1295 peptide, from the bench to the phase 2 trial that stopped.
Ipamorelin came out of a different programme, at Novo Nordisk in Denmark. It is five residues long, it binds the receptor that ghrelin later turned out to occupy, and it was selected precisely because it released GH without the cortisol and prolactin that earlier GHRPs also released [3]. Its terminal half-life in men is about 2 hours [4]. It has never been approved as a medicine.
The vial sold under the combined name in the research market almost always contains the linker-free version of CJC-1295, called Mod GRF 1-29 on forums, together with ipamorelin. If the reason for that choice is not obvious, the guide on CJC-1295 DAC vs no DAC walks through it: a linker designed to keep a peptide in the blood for a week has no logic next to a peptide cleared in two hours.
Why are CJC-1295 and ipamorelin studied together?
The figure below is the one measurement that matters here: growth hormone comes in pulses, and a week-long GHRH signal lifted the floor between them without touching the pulses themselves.
Figure 1
- one week after CJC-1295 (study arm)
- before administration
Growth hormone is released in pulses, mostly at night. A GHRH-type peptide raises the amount available for each pulse; a GHRP-type peptide acts through a second receptor, the one ghrelin binds, and the two effects add up to more than either alone. In 1990, Bowers and colleagues gave 18 normal men GHRP-6 alone, GHRH(1-44) alone, and the two together: the combination released GH synergistically, more than the sum of the two alone [6]. Research interest in pairing a GHRH analogue with a GHRP rests on that observation.
- GHRH receptorAmount
- Ghrelin receptorTrigger
- Both at onceBigger burst
The second thing the record shows is that a long-acting GHRH analogue does not flatten the rhythm. Ionescu and Frohman sampled blood every 20 minutes through the night before and one week after a single administration of CJC-1295: the pulses kept their number and their height, the trough between them rose 7.5-fold, mean GH rose 46 % and IGF-1 45 % [2].
| Study | What the authors wrote |
|---|---|
| Teichman et al., 2006 J Clin Endocrinol Metab, two placebo-controlled trials (summary) | Mean plasma GH rose 2- to 10-fold for 6 days or more, and mean plasma IGF-I 1.5- to 3-fold for 9 to 11 days. |
| Ionescu and Frohman, 2006 J Clin Endocrinol Metab, overnight sampling | GH secretion was increased after CJC-1295 administration with preserved pulsatility. The frequency and magnitude of GH secretory pulses were unaltered. |
| Raun et al., 1998 European Journal of Endocrinology, Novo Nordisk | Very surprisingly, ipamorelin did not release ACTH or cortisol in levels significantly different from those observed following GHRH stimulation. |
What the published trials measured
| Study | Who | What was given | What was found |
|---|---|---|---|
| Teichman 2006 [1] | healthy adults, 21 to 61 | CJC-1295 DAC, single then repeated, vs placebo | GH 2 to 10-fold for 6 days or more; IGF-1 1.5 to 3-fold for 9 to 11 days; half-life 5.8 to 8.1 days |
| Ionescu 2006 [2] | healthy men, 20 to 40 | CJC-1295 DAC, single administration | trough GH ×7.5, mean GH +46 %, IGF-1 +45 %, pulses unchanged |
| Gobburu 1999 [4] | healthy men, 8 per level | ipamorelin, pharmacokinetic study | half-life 2 h; one GH episode peaking at 0.67 h |
| Beck 2014 [5] | 114 participants, post-operative setting | ipamorelin vs placebo, up to 7 days | primary endpoint not met (p = 0.15) |
That is the whole human record for the two molecules: two trials for CJC-1295, one pharmacokinetic study and two phase 2 trials for ipamorelin, one of which has never published its results. The record of each molecule, from synthesis to the stopped phase 2 trial, is on CJC-1295 peptide.
What did the published studies of CJC-1295 and ipamorelin measure?
The published studies measured hormones and kinetics: growth hormone, IGF-1, the shape of the GH pulses, the half-life, and in swine ACTH and cortisol. The table lists each endpoint with the study that reported it.
| Endpoint | What the study reported | Source |
|---|---|---|
| Growth hormone | Mean GH 2 to 10-fold for 6 days or more after one CJC-1295 DAC administration; one GH episode per ipamorelin administration in the kinetic study | Teichman 2006 [1], Gobburu 1999 [4] |
| IGF-1 | 1.5 to 3-fold for 9 to 11 days; +45 % one week after one administration | Teichman 2006 [1], Ionescu 2006 [2] |
| GH pulsatility | CJC-1295 DAC: pulse number and height unchanged, trough ×7.5 | Ionescu 2006 [2] |
| ACTH and cortisol | Not raised by ipamorelin in swine, at more than 200 times the GH ED50; not reported in the human trials | Raun 1998 [3] |
| Clinical endpoint | The one completed phase 2 trial of ipamorelin missed its primary endpoint (p = 0.15) | Beck 2014 [5] |
| GHRH plus GHRP, together | Synergistic GH release shown once, in 1990, with two older cousins (GHRH(1-44) and GHRP-6) in 18 men; never with these two | Bowers 1990 [6] |
So the published record is hormonal: in separate studies the two peptides raised pituitary GH release, and CJC-1295 did so for a week at a time. No study has tested the pair, and this site draws no conclusion beyond the measurements. The one GHRH analogue that did complete a clinical programme, tesamorelin, shows what a full record looks like: a 412-participant phase 3 trial, one primary endpoint, one approval [10].
What CJC-1295 ipamorelin costs in 2026
- per mg, US vendors, 10 mg vial, 21 Sep 2026
- $6.00–10.00
- per mg at OXpeptides, Europe, 16 Oct 2026
- €8.19
- vendors read on their own pages
- 9
The research blend is sold by the vial, almost always 10 mg: 5 mg of linker-free CJC-1295 and 5 mg of ipamorelin. At the US vendors in the shortlist the list price ran from $59.99 to $99.99 on 21 Sep 2026, so $6.00 to $10.00 per milligram before any code. In Europe the same format was €81.90 at OXpeptides on 16 Oct 2026, €8.19 per milligram, shipping €9.90 and free from €120. The spread is not about the peptides, which are commodity syntheses: it tracks what sits around the vial, a per-lot certificate from a named laboratory, a registered company, a reship guarantee, 3-D Secure payment.
Only research vials are compared here: the same 10 mg format, priced per milligram, read on the same day. There is no approved product to compare them with, and since the FDA placed ipamorelin acetate in category 2 of its bulk-substances list in September 2023, no compounded preparation offers a reference price either [8].
Three questions people ask next
Is the blend one vial or two? One. In the research market the two peptides are pre-blended in one lyophilised vial, 5 mg of each in the 10 mg format, and the certificate has to name both compounds with the quantity of each. These are research reagents, not medicines.
Is it sold in any other form? No. The research product is a lyophilised powder in a sealed vial; no other form of either peptide has published data, and anything sold as "CJC-1295 pills" corresponds to no published study.
How is it different from tesamorelin? Tesamorelin is another GHRH analogue, and the only one of the three that finished its programme: a 412-participant phase 3 trial and an approval in the United States on 10 November 2010 for one indication [10]. CJC-1295 stopped in 2006. No trial has combined tesamorelin with ipamorelin either. The records are side by side in tesamorelin ipamorelin vs CJC-1295 ipamorelin, and sermorelin, the parent sequence that was once a licensed medicine, in sermorelin vs CJC-1295 ipamorelin.
What is not known
Three gaps matter more than the rest. First, the combination has never been tested in a published trial, so any claim about "CJC-1295 ipamorelin results" is an extrapolation from separate studies. Second, the linker-free CJC-1295 that fills the research vials has no human pharmacokinetic study of its own; its clearance is inferred from the parent GHRH(1-29) sequence. Third, both development programmes stopped: ConjuChem's phase 2 trial was terminated in 2006, and Helsinn's 320-participant ipamorelin trial completed in 2014 without posting results.
Regulatory status follows from that. Neither molecule is approved by the FDA or the EMA. In September 2023 the FDA placed ipamorelin acetate in category 2 of its list of compounding bulk substances that may present significant safety risks, on the ground of possible immunogenicity [8], and both molecules are named in class S2 of the WADA Prohibited List [9]. How the two forms of CJC-1295 differ, and which one a blend contains, is set out in CJC-1295 DAC vs no DAC.
What is in a "CJC-1295 ipamorelin" vial
Figure 3
In the research-use market the combined name designates one lyophilized vial holding both peptides in equal mass, typically 5 mg of Mod GRF 1-29 and 5 mg of ipamorelin in a 10 mg vial. Because the two molecules differ in mass by a factor of almost five (3,367.9 against 711.9 g/mol), equal mass means about 4.7 molecules of ipamorelin for every molecule of the GHRH analogue. A certificate of analysis for such a vial has to name both compounds found, linker-free CJC-1295 rather than CJC-1295 with DAC, and give the measured quantity of each in mg and the purity in %, or the vial is not what its label says. OXpeptides ships the blend lyophilized, sealed and tracked from the EU.
Before paying anywhere, four things can be checked on the listing itself:
- the certificate names both compounds found, linker-free CJC-1295 and ipamorelin, with the quantity of each in mg and the purity in %;
- the testing laboratory is independent and named, and the report can be verified with it by its task number and key;
- the price and the mass of the vial in mg are visible without an account;
- the shop states where it ships from, a delivery window and a tracking number.