DOSAGE SPEC

CJC-1295 Dosage in the Research Literature

What the indexed phase-1 trials administered, at what intervals, by what route. Research dosing, set out as a specification — not a clinical recommendation.

Dosages studied in published CJC-1295 trials

The Teichman 2006 phase-1 single-ascending-dose arm administered single subcutaneous doses of CJC-1295 with DAC at 30, 60, 125, or 250 µg/kg in healthy adults ^[1]. The multi-dose arm administered 60 µg/kg subcutaneously either weekly or every other week for 49 days ^[16]. The Alba 2006 murine GHRH-knockout study administered approximately 8 to 22 µg/kg subcutaneously once daily ^[3]. These are the published dose ranges for CJC-1295 with DAC. The no-DAC variant (modified GRF 1-29) does not have a comparable single-protocol phase-1 publication; research-protocol dosing for the short-half-life variant is heterogeneous across the literature because the ~30-minute half-life requires multiple-times-daily administration to maintain meaningful receptor occupancy. None of these dose ranges constitute a clinical recommendation. CJC-1295 is not FDA-approved for any indication ^[13] and no labeled dose exists.

CJC-1295 half-life and pharmacokinetics

CJC-1295 half-life

Plasma half-life of CJC-1295 with DAC, measured in the Teichman 2006 phase-1 trial in healthy adults: approximately 5.8 to 8.1 days ^[1]. The DAC linker — a maleimidopropionic-acid lysine derivative at the C-terminus — covalently binds the free Cys34 thiol on circulating serum albumin, and the albumin tether is what produces the multi-day residence ^[5]. CJC-1295 without DAC (modified GRF 1-29): approximately 30 minutes. Native unmodified sermorelin / GHRH (1-29): approximately 7 to 20 minutes ^[10]. Each modification step — the four sequence substitutions, then the DAC linker — extends the pharmacokinetic window by roughly an order of magnitude. The DAC half-life of ~7-8 days is what sets the dosing-interval specification: weekly or every-other-week intervals were chosen for the Teichman 2006 multi-dose arm because they correspond to roughly one half-life and two half-lives between doses, respectively.

How long CJC-1295 stays detectable

CJC-1295 with DAC has a published half-life of approximately 7 to 8 days ^[1]. Detectable plasma levels accordingly persist for roughly four to five elimination half-lives — about four to five weeks — after a single dose. Modified GRF (1-29) clears within hours. WADA-accredited anti-doping laboratories have validated LC-MS detection methods for CJC-1295 in plasma and urine, used for in- and out-of-competition testing of athletes subject to the WADA Code ^[12]. The detection window in anti-doping practice tracks the pharmacokinetic elimination window.

Dosing frequency in CJC-1295 trials

Because of the ~7-8 day half-life of the DAC variant, the published multi-dose phase-1 protocol used weekly or every-other-week subcutaneous dosing for 49 days at 60 µg/kg ^[16]. Cumulative IGF-1 elevation above baseline was sustained throughout the dosing window. The no-DAC variant has been administered more frequently in research because its ~30-minute half-life does not support sustained receptor occupancy from a single daily dose; published modified-GRF (1-29) research protocols accordingly use multiple-times-daily administration. There is no FDA-approved CJC-1295 protocol ^[13].

Injection routes used in CJC-1295 research

Published phase-1 trials of CJC-1295 with DAC administered the peptide by subcutaneous injection into abdominal or thigh subcutaneous tissue ^[17]. This is the only route with peer-reviewed human pharmacokinetic data for the DAC variant. No published trial has compared intramuscular or intravenous administration of CJC-1295 with DAC in humans ^[17]. Murine studies have used subcutaneous and intraperitoneal routes ^[3]. The peptide is degraded in the gastric environment, so oral administration is not a studied research route.

Stability and storage

Lyophilized CJC-1295 peptide is reported stable for years at -20 °C. Once reconstituted in aqueous diluent, stability is limited, and published handling recommendations call for cold-chain storage of reconstituted solution. These are storage parameters reported in the research literature for laboratory handling of the compound — not a vendor or pharmacy specification.

Half-life timeline spec sheet comparing a single sustained teal DAC envelope to a series of coral no-DAC dose spikes on cool-white — One DAC dose maintains coverage across a week; the no-DAC variant requires multiple-times-daily administration.

Three pulsatile GH waveforms drawn as teal strokes on a baseline rule with a coral spec-chip floating to the right on cool-white — Pulsatile GH release preserved under sustained DAC receptor occupancy.