# CJC-1295 Dosage in the Research Literature

> CJC-1295 dosage as set out in published phase-1 trials: single subcutaneous doses of 30-250 µg/kg, weekly or every-other-week multi-dose protocols, ~7-8 day half-life for the DAC variant.

*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

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.

## References

[1] Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged Stimulation of Growth Hormone (GH) and Insulin-Like Growth Factor I Secretion by CJC-1295, a Long-Acting Analog of GH-Releasing Hormone, in Healthy Adults. J Clin Endocrinol Metab. 2006;91(3):799-805. doi:10.1210/jc.2005-1536 https://academic.oup.com/jcem/article/91/3/799/2843281
[3] Alba M, Fintini D, Sagazio A, Lawrence B, Castaigne JP, Frohman LA, Salvatori R. Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. Am J Physiol Endocrinol Metab. 2006;291(6):E1290-E1294. doi:10.1152/ajpendo.00201.2006 https://pubmed.ncbi.nlm.nih.gov/16822960/
[5] Henninge J, Pepaj M, Hullstein I, Hemmersbach P. Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation. Drug Test Anal. 2010;2(11-12):647-650. doi:10.1002/dta.158 https://pubmed.ncbi.nlm.nih.gov/21204297/
[10] Frohman LA, Thominet JL, Webb CB, Vance ML, Uderman H, Rivier J, Vale W, Thorner MO. Pharmacokinetics of growth hormone releasing factor [GRF(1-29)NH2] in normal men. J Clin Invest. 1984;73(5):1304-1311. doi:10.1172/JCI111574 https://www.jci.org/articles/view/111574
[12] World Anti-Doping Agency. World Anti-Doping Code International Standard — Prohibited List 2025. WADA-AMA. https://www.wada-ama.org/en/prohibited-list
[13] U.S. Food and Drug Administration. FDA Briefing Document, Pharmacy Compounding Advisory Committee Meeting — CJC-1295 bulk drug substance nomination. 2023. https://www.fda.gov/media/183819/download
[16] Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged Stimulation of Growth Hormone (GH) and Insulin-Like Growth Factor I Secretion by CJC-1295, a Long-Acting Analog of GH-Releasing Hormone, in Healthy Adults — multi-dose arm. J Clin Endocrinol Metab. 2006;91(3):799-805. doi:10.1210/jc.2005-1536 https://academic.oup.com/jcem/article/91/3/799/2843281
[17] Teichman SL et al., subcutaneous administration route as described in the CJC-1295 phase-1 pharmacokinetic protocol — see reference [1]. doi:10.1210/jc.2005-1536 https://academic.oup.com/jcem/article/91/3/799/2843281

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The CJC-1295 research record, set out as a specification — not a clinic, not a vendor, not a prescription.