A literature review of CJC-1295 dosage: the weight-scaled weekly doses used in the published human trials of the DAC form, the half-life data behind that cadence, and reconstitution math for a 10 mg research vial.
CJC-1295 is one of the few research peptides where the word "dosage" is genuinely ambiguous, because two different molecules are sold under the name. The compound studied in the published human trials is CJC-1295 with DAC — a GHRH(1–29) analog carrying a Drug Affinity Complex linker that binds covalently to circulating albumin. The compound usually sold as "CJC-1295 no DAC" is the tetrasubstituted GHRH(1–29) fragment (modified GRF 1–29) without that linker. Their pharmacokinetics differ by two orders of magnitude, and so does the depth of the literature behind them. What follows is a review of what the published research actually administered — not a protocol.
The primary human reference is Teichman and colleagues (Journal of Clinical Endocrinology & Metabolism, 2006): two randomized, double-blind, placebo-controlled ascending-dose trials of 28 and 49 days, using single subcutaneous doses in one arm and two or three weekly or biweekly injections in the other. Doses were weight-scaled in micrograms per kilogram, not fixed microgram amounts. The report singled out 30 and 60 µg/kg as the doses with the most favourable tolerability profile.
The response was durable rather than acute. After a single injection, mean plasma GH rose 2- to 10-fold in a dose-dependent manner for six days or more, and mean IGF-I rose 1.5- to 3-fold for nine to eleven days. With repeated dosing, IGF-I remained above baseline for as long as 28 days — evidence of accumulation across a weekly cadence.
Ionescu and Frohman (JCEM, 2006) gave healthy men a single dose of 60 or 90 µg/kg and profiled overnight GH secretion a week later. Pulse frequency and pulse amplitude were unchanged; what moved was the trough. Basal GH rose roughly 7.5-fold, mean GH by about 46%, and IGF-I by about 45%, with the IGF-I rise tracking basal rather than pulsatile GH. That is the mechanistic argument for the long-acting form: it raises the floor of GH secretion without flattening the pulse architecture.
Two things follow for anyone reading vendor dosing charts. First, µg/kg scaling means the published doses are large in absolute terms — 60 µg/kg is about 4.2 mg for a 70 kg subject, not the 100 µg figures that circulate online. Second, those two numbers describe different experiments: the weekly trial doses and the "100 mcg two or three times weekly" convention found on forums do not come from the same source.
The no-DAC analog carries four substitutions on the GHRH(1–29) backbone (positions 2, 8, 15, and 27) that resist dipeptidyl peptidase-4 cleavage and oxidation. Without the albumin linker, exposure is measured in minutes. Unmodified sermorelin — GHRH(1–29) itself, marketed as Geref before its 2008 withdrawal from the US market — has a plasma half-life on the order of ten minutes and carried a label dose of 0.03 mg/kg subcutaneously at bedtime for paediatric GH deficiency. The commonly repeated ~30-minute half-life for the tetrasubstituted no-DAC version appears in secondary sources but not, as far as we can find, in a peer-reviewed human pharmacokinetic study. Treat it as an estimate, not a measurement.
The practical consequence in the literature is that short-acting GHRH analogs are studied on frequent, small, pulse-timed administration schedules, while the DAC form is studied weekly. Cadence follows half-life; it is not a stylistic choice. Our CJC-1295 with or without DAC article covers the structural difference in more depth, and growth-hormone secretagogues explained places both alongside the ghrelin-mimetic class they are frequently paired with in research designs.
Both CJC-1295 no DAC and CJC-1295 with DAC ship as 10 mg lyophilized vials. The arithmetic is the same for either.
Reconstituting 10 mg with 2 mL of bacteriostatic water gives 5 mg/mL — 5,000 µg per mL. On a U-100 insulin syringe, one unit is 0.01 mL, so one unit holds 50 µg and ten units hold 500 µg. Scaling a trial-equivalent 60 µg/kg dose for a 70 kg model (4.2 mg) at that concentration would require 0.84 mL — 84 units, most of a full syringe. That is a useful sanity check: if bench arithmetic returns a volume that seems implausible for the vial size, the concentration, not the peptide, is usually the variable to change. Reconstituting more concentrated (1 mL, giving 10 mg/mL) halves every draw volume.
Work the conversions yourself rather than copying a chart: see peptide dosing math for the mg/mcg/IU conversions and reconstitution 101 for solvent selection, mixing technique, and post-reconstitution storage. Reconstituted GHRH analogs are refrigerated and have a materially shorter usable window than the lyophilized powder.
The DAC form never completed clinical development. In July 2006, ConjuChem halted a phase 2 trial in HIV-associated visceral obesity — 192 participants on once-weekly escalating regimens of 60/90/120 or 60/120/240 µg/kg — after the death of a study participant. The relationship of that death to the study drug was reported as under investigation and was never publicly resolved; development did not resume, and CJC-1295 has no regulatory approval in any jurisdiction. GHRH analogs, including CJC-1295, sermorelin, and tesamorelin, are also prohibited at all times under section S2 of the WADA Prohibited List.
That is the honest ceiling on the data: a small number of short phase 1 trials in healthy adults, one halted phase 2, and no long-term exposure record at all.
How long is CJC-1295's half-life? For the DAC form, the published estimate is 5.8 to 8.1 days, driven by covalent binding to serum albumin. The no-DAC analog is short-acting — minutes rather than days — though a primary human pharmacokinetic figure for it does not appear to have been published.
Why are the trial doses given in µg/kg? Because the phase 1 and phase 2 protocols scaled doses to body weight. Converting them to fixed microgram amounts requires assuming a weight, which is why published figures and vendor charts often disagree by an order of magnitude.
Does the DAC form suppress natural GH pulses? Not in the one study that measured it directly. Ionescu and Frohman found pulse frequency and amplitude unchanged after a single injection, with basal (trough) GH accounting for the rise in mean GH and IGF-I.
Is there a published long-term dosing schedule? No. The longest published trials ran 28 and 49 days, and the phase 2 program was stopped early. Any schedule described as long-term is extrapolation, not evidence.
Is CJC-1295 approved for human use? No. It was never approved in any jurisdiction, and material sold for research is not manufactured, tested, or labelled for human administration.
