CJC-1295 FAQ: 28 Questions from the Research Literature

CJC-1295 is a synthetic GHRH analog that binds pituitary GHRH receptors, stimulating GH secretion via a Gαs/cAMP/PKA cascade. The with-DAC form produces sustained tonic GH elevation (2–10-fold, lasting ≥6 days per Teichman 2006^[1]); the no-DAC form produces a discrete pulsatile GH response lasting ~30–60 minutes per injection. Downstream: IGF-1 rises 1.5- to 3-fold^[1]; GH stimulates distal nephron sodium reabsorption, increasing extracellular volume.^[8]

The Teichman 2006 human trial documented injection-site erythema (~23%), transient flushing and dizziness (~22%), and headache at higher doses; no serious adverse reactions occurred at any dose.^[13] Fluid retention is the most consistently reported effect in use reports, attributable to GH-stimulated distal nephron sodium reabsorption.^[8] The FDA 2024 compounding docket identified potential immunogenicity concerns (aggregation risk) for injectable compounded formulations.^[16]

No direct testosterone effect has been demonstrated in CJC-1295 studies. CJC-1295 acts on the GH/IGF-1 axis via pituitary somatotroph GHRH receptors; the Teichman 2006 and Ionescu 2006 studies did not measure testosterone, LH, or FSH.^[19] Indirect IGF-1-mediated androgen-signaling effects are theoretically plausible but unconfirmed by controlled human data.

CJC-1295 with DAC — half-life 5.8–8.1 days — was studied at once-weekly or biweekly SC injection schedules in the Teichman 2006 ascending-dose trial.^[1] The no-DAC form (Mod GRF 1-29), with a ~30-minute half-life, requires multiple daily injections in research protocols designed to maintain continuous GH stimulation.

Measurable GH and IGF-1 elevation occurs within 2–6 hours of administration in the Teichman 2006 trial.^[1] Body composition changes in rodent models appear after 4–8 weeks of sustained dosing. Human body-composition data for CJC-1295 does not exist in adequately powered clinical trials; the rodent timeline cannot be directly extrapolated to humans.

The CJC-1295 + ipamorelin stack amplifies GH pulse magnitude via dual GHRH-R + GHS-R1a stimulation. More pronounced water retention and flushing than either peptide alone have been reported,^[13] consistent with higher GH-driven distal nephron sodium reabsorption.^[8] Injection-site reactions at both administration sites are documented. No peer-reviewed combined adverse-event study exists.

Preclinical research models test the CJC-1295 + ipamorelin combination for enhanced GH secretion synergy, lean body mass support, bone density,^[10] and recovery from musculoskeletal injury.^[11] GH-secretagogue class human data (tesamorelin RCTs) shows visceral fat reduction.^[9] Human data specifically for the combination is limited to small pilot studies and observational reports.

The DAC (Drug Affinity Complex) moiety covalently binds CJC-1295 to circulating albumin via a maleimide–Cys34 thioether bond, extending half-life from ~30 minutes (no-DAC) to approximately 5.8–8.1 days (with-DAC).^[3][14] This fundamentally changes the dosing architecture from multiple daily pulses to once-weekly or biweekly injections, and shifts the GH profile from pulsatile to tonic.

Mod GRF 1-29 is the no-DAC version of CJC-1295. Both share the same modified 29-amino-acid GHRH backbone with four amino-acid substitutions, but lack the DAC albumin-binding extension. Market names 'Mod GRF 1-29,' 'Modified GRF 1-29,' and 'CJC-1295 no DAC' refer to the same molecule.^[14]

This site does not recommend a course of research use. The documented tradeoff: with-DAC provides sustained tonic GH elevation (weekly dosing; blunted natural pulsatility); no-DAC preserves physiologic pulsatile release (daily injections). The downstream implications of each GH pulse profile are studied but not resolved in human controlled trials.^[14]

In published and observational research protocols, the two peptides are co-administered subcutaneously. Ipamorelin terminal half-life is ~2 hours with a GH peak at ~0.67 hours post-injection;^[6] CJC-1295 with DAC covers the background GH elevation continuously. Timing relative to fasted state is a recurring design variable — insulin elevation blunts pituitary GH response.^[1][3]

CJC-1295 amplifies GH release via GHRH-R agonism; ipamorelin stimulates GH release via a distinct GHS-R1a pathway. The two mechanisms are independent and their GH-secretagogue actions are additive at the pituitary level — GHRH + GHRP combined stimulation produced significantly greater pulsatile GH than either alone in the Norman 2013 infusion study (P<0.01).^[7] Ipamorelin's selectivity avoids the cortisol and ACTH elevation associated with GHRP-2.^[5]

Yes. 'CJC-1295 no DAC' and 'Modified GRF 1-29' (Mod GRF 1-29) are interchangeable market names for the 29-AA GHRH analog lacking the albumin-binding DAC extension.^[14] The molecule is the same; only the name varies by vendor or community convention.

CJC-1295 without DAC: plasma half-life approximately 30 minutes (Jetté et al. 2005^[3]). CJC-1295 with DAC: terminal half-life 5.8–8.1 days (Teichman et al. 2006^[1]). The difference — ~250-fold — arises from DAC-mediated covalent albumin binding.

Fluid retention is among the most consistently reported effects across GH-axis stimulation. The mechanism is GH-stimulated sodium reabsorption in the distal nephron, which prevents pressure natriuresis and increases extracellular volume.^[8] Severity correlates with dose; the effect is typically transient in rodent wash-out studies.

CJC-1295 is not FDA-approved for any indication. It was reviewed by the FDA PCAC in December 2024 for 503A bulk-drug compounding inclusion (docket FDA-2024-N-4777); the FDA identified potential immunogenicity concerns.^[16] It remains a research compound only as of 2026.

CJC-1295 is a peptide — a short chain of amino acids — not a steroid. It has no steroidal ring structure and does not bind androgen, estrogen, or glucocorticoid receptors. It acts exclusively on pituitary GHRH receptors.^[12]

Sermorelin is a truncated native GHRH(1-29) analog with unmodified amino acids and a half-life of ~10–12 minutes, rapidly cleaved by DPP-IV. CJC-1295 has four substitutions that resist DPP-IV cleavage (no-DAC: ~30 min; with-DAC: 5.8–8.1 days via albumin conjugation). Sermorelin has an FDA-approval history; CJC-1295 does not.^[15]

Unlike exogenous GH, which suppresses pituitary output via negative feedback, CJC-1295 stimulates the pituitary's own production. Ionescu and Frohman 2006 confirmed GH pulsatility is preserved during continuous CJC-1295 administration.^[2] Post-study GH suppression has not been reported in published trials.^[18] Long-term (>3 months) data does not exist.

Published protocols use both continuous and cycled designs (5 on / 2 off). No peer-reviewed comparative cycling data in humans exists. The Teichman 2006 trial ran to 49 days continuous;^[1] the GHRH-knockout mouse study used five continuous weeks.^[4] The cycling question remains open in the published record.

Published clinical studies run from four to twelve weeks. The Teichman 2006 study observed sustained GH and IGF-1 elevation over fourteen days from a single dose;^[1] multi-week protocol data beyond the published trials comes primarily from compounding-pharmacy clinical-use reports not in the peer-reviewed literature.

Reconstituted CJC-1295 in bacteriostatic water should be stored refrigerated at 2–8°C. Based on general peptide stability guidelines, refrigerated stability of approximately 30 days post-reconstitution is the consensus for peptides of comparable size; freeze-thaw cycles risk peptide bond degradation and are generally avoided in laboratory protocols.

Preclinical rodent models demonstrate lean mass preservation and fat mass reduction with combined GHRH + GHRP administration; the pathway is GH-driven IGF-1 elevation promoting myogenesis and lipolysis.^[11] GHRH-class human RCTs (tesamorelin) demonstrate significant visceral fat reduction.^[9] Human clinical outcome data specifically for the CJC-1295 + ipamorelin combination is sparse and mostly observational.

MK-677 (ibutamoren) is orally active and produces sustained 24-hour GH elevation. CJC-1295 + ipamorelin is injectable and produces pulsatile GH. The two differ in route, GH pulse architecture, and side-effect character.^[20] No head-to-head comparative human RCT exists; the comparison is mechanistic only.

CJC-1295 (MW ~3,647 Da) has no documented oral bioavailability. Gastric and intestinal proteases degrade peptides of this size before systemic absorption.^[17] All published human and rodent studies use subcutaneous injection exclusively.

Insulin and elevated blood glucose blunt pituitary GH response via somatostatin-mediated suppression. Administering GHRH analogs in a fasted state maximizes the detectable GH pulse amplitude — a design rationale documented in both the Jetté 2005 and Teichman 2006 CJC-1295 papers.^[1][3]

Community reports and small case series note vivid dreams and transient sleep disruption when the no-DAC form is dosed close to bedtime, attributed to the GH pulse coinciding with sleep onset. Systematic sleep architecture studies for this compound are absent from the peer-reviewed literature; this remains an open empirical question.

GHRP-2 produces larger GH pulses combined with GHRH but elevates ACTH and cortisol via non-selective GHS-R binding. Ipamorelin is highly selective for GHS-R1a — no ACTH or cortisol elevation at doses 200× the GH ED50.^[5] Selectivity is the documented differentiator; at equivalent GH-stimulating doses, ipamorelin has a cleaner hormonal profile for GH-specific research designs.

CJC-1295 stimulates endogenous GH production, preserving pulsatility and negative feedback; synthetic GH bypasses these controls. No head-to-head clinical efficacy trial exists.^[18] The two approaches differ fundamentally in pharmacology and regulatory status — exogenous GH has approved human indications; CJC-1295 does not.

No direct testosterone effect has been demonstrated. CJC-1295 acts on the GH/IGF-1 axis via pituitary GHRH receptors, which are expressed on somatotrophs, not gonadotrophs.^[19] Indirect IGF-1-mediated androgen-signaling effects are theoretically plausible but unconfirmed by controlled human data.