CJC-1295

Native GHRH is destroyed in the blood within minutes, mainly by dipeptidyl peptidase-IV, which is why GHRH itself has never been a practical treatment [4]. CJC-1295 is the engineering answer: a tetrasubstituted GHRH(1-29) carrying a maleimide group that reacts with the free thiol on cysteine-34 of serum albumin, so the peptide is effectively carried around attached to a protein that circulates for weeks. In rats, the conjugate appeared on the albumin band within 15 minutes and was still there beyond 24 hours, and gave a fourfold larger growth hormone response than plain GHRH(1-29) [1].

The human trial. Two randomised, placebo-controlled, double-blind ascending-dose studies, of 28 and 49 days, in healthy adults aged 21-61. A single subcutaneous injection raised mean growth hormone 2- to 10-fold, dose-dependently, for six days or more, and IGF-1 1.5- to 3-fold for 9-11 days. The estimated half-life was 5.8-8.1 days. With repeated weekly or biweekly doses, IGF-1 stayed above baseline for up to 28 days, showing a cumulative effect. No serious adverse reactions were reported, and the authors singled out 30 and 60 ug/kg as the best tolerated [2]. A proteomics substudy in 11 young men looked for markers of the resulting GH/IGF-1 activation and found changes in apolipoprotein A1, transthyretin and albumin fragments [5].

That is all the human data there is. Nobody has published what CJC-1295 does to muscle, fat, strength, bone, glucose or any clinical outcome, at any duration.

A naming problem. Two different things are sold as CJC-1295. The compound described above is CJC-1295 with DAC (Drug Affinity Complex), the albumin-binding version that was trialled. "CJC-1295 without DAC" is modified GHRH(1-29) — the same backbone substitutions, no albumin anchor — with a duration of action measured in minutes to hours, and no trial of its own [3]. The pharmacokinetics above apply only to the DAC version. CJC-1295 has been found in seized unlabelled preparations [6] and is prohibited in sport under section S2 of the WADA list [6].

CJC-1295 activates the pituitary GHRH receptor, the same receptor as sermorelin and tesamorelin [1]. Because it works upstream, the pituitary still releases growth hormone in pulses and the normal negative feedback through IGF-1 and somatostatin remains in place — the usual argument for secretagogues over injected growth hormone.

Its novelty is entirely pharmacokinetic. Four substitutions in the GHRH(1-29) backbone block enzymatic degradation, and a maleimidopropionamide on the C-terminal lysine forms a covalent bond with albumin in the bloodstream [1]. A single D-Ala2 substitution alone already cuts metabolic clearance roughly in half and lengthens the half-life from 4.3 to 6.7 minutes [4]; the albumin conjugation takes it to days.

The open question is whether continuous stimulation of the GHRH receptor is a good idea. In children given GHRH(1-29) by continuous subcutaneous infusion, the 24-hour growth hormone output rose at first and then fell below where it started by six months, with pituitary desensitisation and GHRH antibodies among the suspected causes [7]. CJC-1295 holds GHRH receptor stimulation up for days at a time, and no study has run long enough to see whether the same thing happens.

CJC-1295 with DAC is a 29-amino-acid peptide with four substitutions plus an N-epsilon-3-maleimidopropionamide lysine at the C terminus, which is the part that binds albumin [1]. The version sold as "CJC-1295 without DAC", also called modified GRF(1-29), lacks that group and lasts hours rather than days [3]. Anything sold under the bare name CJC-1295 may be either; there is no way to tell from the label. Analytical methods now exist to detect GHRH analogues in urine at picogram levels [8].

The trial reported no serious adverse reactions across both studies, and named 30 and 60 ug/kg as the doses that were tolerated best — implying the higher doses were tolerated less well, though the abstract does not detail how [2]. The full text was not available for this entry.

Beyond that, human safety data do not exist. There is nothing on glucose, nothing on months of use, nothing on what sustained IGF-1 elevation does. A 2026 review of this whole class notes the adverse effects seen across GHRH analogues and secretagogues — fluid retention, joint and muscle pain, injection-site reactions, dysglycaemia, and raised prolactin and cortisol with some agents — and the general problem that products bought outside a pharmacy may not contain what the label says [3].

No human interaction studies exist. GHRH analogues and ghrelin-receptor agonists are synergistic on growth hormone release [9], which is the basis for the common practice of combining CJC-1295 with ipamorelin, but no trial has tested that combination.