CJC-1295 Dosage in Published Research: Human and Preclinical Data
CJC-1295 Dosage Ranges in Published Studies
The CJC-1295 dosage literature is anchored by the Teichman et al. (2006) Phase I/II dose-escalation study — the only published human pharmacokinetic trial [1]. The trial used single subcutaneous doses across four cohorts: 30, 60, 90, and 125 mcg/kg in healthy adults. Dose-dependent GH and IGF-1 elevation was observed across all cohorts. The compound was well tolerated at 30–60 mcg/kg. Higher doses (90–125 mcg/kg) produced vasodilatory reactions including flushing in some subjects.
Preclinical rodent studies used substantially wider dose ranges. The Jette et al. (2005) rat studies used subcutaneous injection at doses sufficient to produce a 4-fold GH AUC advantage over native hGRF(1-29) [4]. The Alba et al. (2006) mouse studies used 2 micrograms per injection administered once daily [5]. Rodent intraperitoneal and intravenous studies in the detection literature used 0.1 mg IV in rats [20]. No validated therapeutic dose exists for any human indication — CJC-1295 is not FDA-approved.
For reference, ipamorelin (the primary stacking partner) was studied in rats at 18, 90, or 450 micrograms per day administered in three daily subcutaneous injections [9]. The MK-677 comparison data used oral doses of 5 mg or 25 mg once daily in human subjects [16].
CJC-1295 Half-Life: DAC vs No-DAC
Half-life is the central pharmacokinetic variable differentiating the two CJC-1295 variants.
CJC-1295 with DAC: 5.8–8.1 days in humans, as measured in the Teichman et al. 2006 Phase II trial across the 30–125 mcg/kg dose range [1]. This extended half-life results from covalent albumin binding. Albumin's long half-life (~19 days) effectively shelters the bound peptide from renal clearance and enzymatic degradation.
CJC-1295 without DAC (Modified GRF 1-29): Approximately 30 minutes in rodent plasma, based on the four amino acid substitutions that confer DPP-IV resistance but without albumin binding. This is roughly 17-fold longer than native GHRH(1-29)'s half-life, but far shorter than the DAC form.
Native GHRH(1-29) (sermorelin): Approximately 10–20 minutes in humans, limited by DPP-IV cleavage at the N-terminus and renal ultrafiltration [13].
The practical consequence: CJC-1295 DAC research models use once-weekly dosing; no-DAC research models use more frequent injections to maintain GHRH-R engagement; sermorelin studies typically use daily or nightly injections. These frequency differences are the direct pharmacokinetic consequence of the half-life differences.
How Long Does CJC-1295 Take to Work in Research Models?
Pharmacokinetic studies in humans showed peak plasma GH elevation within 2–6 hours of a single subcutaneous injection [1]. Mean plasma GH levels remained elevated for 6 days post-injection in the CJC-1295 DAC arm of the Teichman et al. 2006 Phase II trial. IGF-1 elevation, a downstream marker of GH axis activation, was detected for 9–11 days post-injection. After multiple doses in the same trial, IGF-1 remained above baseline for up to 28 days, reflecting the cumulative effect of sustained GHRH-R stimulation on hepatic IGF-1 production.
How Long Does CJC-1295 Stay in Your System?
CJC-1295 without DAC is largely cleared within 4–6 hours in rodent models based on DPP-IV resistance half-life estimates. The DAC form demonstrated sustained elevation of mean plasma GH and IGF-1 concentrations for up to 14 days post-injection in the 2006 human Phase II study, reflecting the long albumin-binding half-life [1]. Detection studies have demonstrated CJC-1295 is measurable in human plasma using immunoaffinity capture and LC-HRMS at sensitivities below 50 pg/mL, and in equine plasma at 180 pg/mL using immuno-affinity-assisted LC-MS/MS [19][20].
CJC-1295 and Ipamorelin Protocols in the Research Literature
Published dosing protocols using CJC-1295 in human trials used subcutaneous administration [1]. Preclinical rodent studies used intraperitoneal injection at doses ranging from 100–500 mcg/kg in various models. Ipamorelin rat studies used three-times-daily subcutaneous injections at 18, 90, or 450 micrograms per day [9]. No published trial has specifically examined the combined CJC-1295/ipamorelin protocol with a defined dosing schedule as the primary study design. The CJC-1295 ipamorelin stack research page covers the mechanistic synergy literature and what the available evidence does and does not support.
What Is the CJC-1295 Dosage Used in Research?
The Teichman et al. 2006 JCEM Phase II trial used single-dose CJC-1295 DAC at 30, 60, 90, or 125 mcg/kg subcutaneously in healthy adults [1]. Preclinical rodent studies have used a range of doses across different administration routes. No validated human therapeutic dose exists — CJC-1295 is not FDA approved for any indication. Any dosing data presented here is strictly from published research protocols and does not constitute a recommendation for human use.