CJC-1295 with DAC

CJC-1295 with DAC is a long-acting GHRH analogue built on Mod GRF 1-29, the 1-29 fragment of the 44-amino-acid GHRH molecule that retains full receptor activity. Four substitutions modify the fragment: position 2 blocks DPP-4 cleavage, positions 8 and 27 prevent deamidation and oxidation, and position 15 enhances bioactivity. Unmodified GHRH has a half-life of roughly 2 minutes; the modified fragment alone reaches about 30 minutes.

The Drug Affinity Complex conjugates the peptide to albumin in circulation, shielding it from proteolysis and extending the half-life to 5.8 to 8.1 days based on Teichman et al. (2006). Jette et al. (2005) identified the albumin bioconjugate mechanism and showed a 4-fold increase in growth hormone area under the curve over 2 hours in rats versus standard GRF 1-29, with the compound detectable in plasma beyond 72 hours.

Pharmacodynamically the DAC version differs from the short-acting analogue in pattern rather than pathway. Both act on pituitary GHRH receptors on somatotrophs. The short-acting form produces a discrete pulse that returns to baseline; the DAC form produces sustained elevation with markedly higher trough levels. Ionescu and Frohman (2006) demonstrated that pulsatility is preserved during continuous stimulation, with trough GH up 7.5 fold, pulse frequency and magnitude unchanged, overall GH up 46 percent and IGF-1 up 45 percent.

Developed by ConjuChem Biotechnologies, CJC-1295 with DAC advanced to Phase 2 trials for HIV-related lipodystrophy, a multicentre randomised placebo-controlled double-blind study that had enrolled 192 participants across North and South America. Development was halted in July 2006 after one participant died in Argentina hours after an eleventh injection; the attending physician concluded the death was most likely from undiagnosed coronary artery disease with plaque rupture and occlusion, unrelated to the peptide. Development was not resumed and the compound holds no FDA approval.

Growth hormone secretion is governed by two complementary inputs. Hypothalamic GHRH acts on GHRH receptors on pituitary somatotrophs, triggering a G protein, cyclic AMP and protein kinase cascade that drives synthesis and release. Gastric ghrelin acts on the GHS-R1a receptor, evoking release of stored growth hormone while simultaneously suppressing somatostatin. Co-activation is synergistic, which is why the largest endogenous pulse occurs in slow-wave sleep when insulin is low, ghrelin is high and GHRH tone is present. Animal data show combined GHRH plus GHRP administration yields peak GH 2 to 5 fold above the additive prediction.

CJC-1295 with DAC occupies only the GHRH arm. It raises secretory capacity without emptying the releasable pool or lifting somatostatin inhibition, hence the standard pairing with a selective ghrelin agonist. Raun et al. (1998) established Ipamorelin as the first selective secretagogue, stimulating GH without meaningful cortisol, ACTH or prolactin elevation even at 200-fold its effective dose, which is why it displaced GHRP-6 and GHRP-2 as the preferred partner.

Albumin binding is the defining pharmacokinetic feature. Sustained receptor occupancy shifts the secretory profile toward elevated troughs rather than sharp peaks and deep valleys. Ionescu and Frohman (2006) concluded that the marked enhancement of trough GH under continuous GHRH stimulation was the primary driver of the IGF-1 rise. Alba et al. (2006) showed once-daily CJC-1295 normalised body weight and length in GHRH knockout mice, with increases in total pituitary RNA and GH mRNA suggesting somatotroph proliferation; 48 or 72 hour intervals improved but did not normalise growth.

Hepatic conversion of GH to IGF-1 mediates most downstream effects, including mTOR activation for muscle protein synthesis, hormone-sensitive lipase-driven lipolysis and collagen synthesis. Negative feedback via IGF-1 and somatostatin remains operative, so the axis is stimulated rather than overridden, unlike exogenous GH or IGF-1 administration. Exogenous GH inhibits the GHRH pathway by roughly 86 percent and the ghrelin pathway by roughly 32 percent through somatostatin elevation, making concurrent use redundant.

The primary pharmacological effect is increased pituitary GH secretion with a secondary rise in hepatic IGF-1. Teichman et al. (2006) recorded GH increases of 2 to 10 fold above baseline for 6 or more days after a single injection, IGF-1 increases of 1.5 to 3 fold for 9 to 11 days, and IGF-1 remaining above baseline for up to 28 days after multiple doses with evidence of a cumulative effect. The DAC form produces sustained exposure rather than discrete pulses, with trough elevation as the main driver of IGF-1 gain.

Sleep architecture responds directly to GHRH signalling, with increased duration and intensity of slow-wave sleep. This is typically the earliest detectable effect and coincides with the largest endogenous GH pulse.

Anabolic effects are IGF-1 mediated: receptor binding on myocytes activates a cascade converging on mTOR to drive muscle protein synthesis, improving recovery and reducing soreness over months rather than days. This depends on an intact androgen background. Blockade of androgen receptor signalling shuts down the downstream IGF-1 cascade, and testosterone directly upregulates intramuscular IGF-1 expression. In women, oestrogen governs whether muscle tissue responds to anabolic signalling; postmenopausal women without replacement show a blunted muscle protein synthesis response to exercise that is restored when oestrogen is replaced.

Lipolytic effects proceed through activation of hormone-sensitive lipase, with a preference for visceral adipose tissue, typically evident around 8 to 12 weeks in those with nutrition and training already controlled. Collagen synthesis and cellular repair improve over 3 to 6 months, affecting skin quality, joint health and connective tissue resilience. Bone mineral density support is a long-horizon outcome relevant to age-related decline in the GH axis. Adequate insulin exposure remains necessary for hepatic IGF-1 conversion, which is worth noting when appetite is suppressed.

Expect a slow, cumulative response profile rather than acute effects. Sleep changes typically present in weeks 1 to 2, reflecting the direct GHRH influence on slow-wave sleep. Training recovery and reduced soreness follow in weeks 2 to 4, sometimes with early skin quality change. Weeks 4 to 8 bring measurable body composition shifts, improved intra-session fullness and early joint comfort change in those with controlled nutrition and training. Weeks 8 to 12 are where lipolysis becomes visibly apparent, slower than caloric restriction or GLP-1 mediated loss but weighted toward visceral fat with lean tissue preservation. Connective tissue outcomes, including skin, joint and tendon resilience, emerge across months 3 to 6.

The half-life is 5.8 to 8.1 days based on Teichman et al. (2006), commonly described as 6 to 8 days. This produces sustained elevation with high troughs rather than discrete pulses, and the subjective experience is correspondingly diffuse. Users report that the without-DAC form delivers more distinct acute effects, including post-injection flushing and warmth, while the DAC form is harder to identify day to day.

The long duration also removes the ability to titrate quickly. Adverse effects such as water retention cannot be cleared within an hour as they can with a 30 minute half-life analogue, and water retention may be more pronounced under sustained elevation.

Objective confirmation is straightforward: measure IGF-1 before starting and again at 4 to 8 weeks. A rise confirms pathway activation. Aggregated anecdotal reports consistently place sleep as the earliest subjective marker and describe body composition change over 8 to 16 week runs, with fat loss frequently recognised only late in the cycle. Recurrent disappointment in user reports stems from expecting faster or more dramatic results than the GH axis delivers.

No published dose-finding studies support the subcutaneous protocols used in practice. Clinical trial dosing was weight-based at 30 or 60 mcg per kg, and the figures below reflect clinical practice patterns rather than trial evidence.

Standard practice is 1 to 2 mg per week subcutaneously, once or twice weekly, for 8 to 12 weeks. The 5.8 to 8.1 day half-life removes any strict timing requirement. Splitting the weekly dose, for instance 1 mg Sunday and 1 mg Wednesday, is sometimes used to flatten levels further but is generally unnecessary given the duration of action.

Insulin binds somatotrophs and suppresses GH release, which makes fasted administration critical for short-acting analogues: at least 2 hours post-prandial before injection and 30 minutes before eating afterwards. With DAC, continuous receptor occupancy renders dietary timing far less relevant, though the same principle applies for optimal response.

The 5-on/2-off convention is unsupported. Acute desensitisation resolves in roughly 60 minutes; chronic desensitisation develops over approximately 16 weeks and reverses in about 4 weeks off, based on Rahim and Shalet (1998) in hexarelin. Two days off addresses neither timescale. Tesamorelin trials that secured FDA approval used daily dosing for 26 weeks, and a two-year MK-677 study used continuous daily dosing with GH and IGF-1 remaining elevated throughout. Continuous use for up to 16 weeks followed by 4 weeks off is the evidence-consistent approach.

Reconstitution: 5 mg vial with 2 mL bacteriostatic water yields 250 mcg per 10 units on an insulin syringe. Refrigerate after reconstitution and use within 28 days.

Stacking is with the ghrelin arm, not a second GHRH analogue; Tesamorelin and Sermorelin are redundant alongside CJC-1295. Exogenous GH or IGF-1 should not be combined, given approximately 86 percent inhibition of the GHRH pathway through somatostatin elevation. Monitor IGF-1 at baseline and every 4 to 8 weeks initially, then every 3 months once stable, alongside fasting glucose and insulin sensitivity. Reduce the dose if carpal tunnel symptoms, joint swelling or excessive water retention appear.

Teichman et al. (2006), published in the Journal of Clinical Endocrinology and Metabolism, comprises two randomised, placebo-controlled, double-blind trials of CJC-1295 with DAC in healthy adults aged 21 to 61: a single ascending dose trial over 28 days and a multiple dose trial with weekly or biweekly injection over 49 days. Single injection produced a 2 to 10 fold rise in GH for 6 or more days and a 1.5 to 3 fold rise in IGF-1 for 9 to 11 days, with an estimated half-life of 5.8 to 8.1 days. Multiple dosing kept IGF-1 above baseline for up to 28 days with evidence of cumulative effect. Doses of 30 or 60 mcg per kg were well tolerated with no serious adverse reactions. Limitations: DAC version only, small samples, no safety data beyond 49 days.

Ionescu and Frohman (2006), same journal, addressed whether continuous GHRH receptor stimulation overrides pulsatility. Pulse frequency and magnitude were unchanged while trough GH rose 7.5 fold, overall GH rose 46 percent and IGF-1 rose 45 percent. The authors attributed the IGF-1 gain primarily to elevated troughs rather than higher peaks.

Alba et al. (2006) in the American Journal of Physiology, Endocrinology and Metabolism used GHRH knockout mice: once-daily dosing normalised body weight and length, whereas 48 or 72 hour intervals improved but did not normalise growth. Total pituitary RNA and GH mRNA rose, suggesting somatotroph proliferation. Translation to humans with intact GHRH signalling is limited.

Jette et al. (2005) in Endocrinology characterised the albumin bioconjugate mechanism, showing a 4-fold increase in GH area under the curve over 2 hours versus GRF 1-29 in rats, with plasma detection beyond 72 hours.

Raun et al. (1998) underpins the Ipamorelin pairing, and Rahim and Shalet (1998) supplies the desensitisation timeline used for cycling. Phase 2 development for HIV-related lipodystrophy, a multicentre randomised placebo-controlled double-blind study enrolling 192 participants, was halted in July 2006 and never resumed.