# CJC-1295 Dosage in the Research Literature

> CJC-1295 dosage in published studies ranged from 30–125 μg/kg SC for the with-DAC form and 2 μg/day in GHRH-knockout mice. This page covers research-documented doses, half-life data, injection timing, cycling protocols, and reconstitution notes.

## Research Doses Documented in the Literature

CJC-1295 dosage in published human trials was administered subcutaneously at 30, 60, 90, and 125 μg/kg in the ascending-dose Teichman 2006 trial [1] and at 60 and 90 μg/kg in the Ionescu and Frohman 2006 GH-pulsatility sub-study [2]. These are the only peer-reviewed human pharmacokinetic datasets for CJC-1295 with DAC. No published human pharmacokinetic study for CJC-1295 without DAC (Mod GRF 1-29) exists.

In the rodent literature, GHRH-knockout mice received 2 μg/day SC once-daily for five weeks [4]. Ipamorelin was administered at 0.5–100 μg/kg SC, two to three times daily in rat bone and catabolism models [10, 11].

All dosing described here is research-context framing. This site makes no human dosing recommendations. CJC-1295 is not FDA-approved for any indication.

## Half-Life: With DAC vs Without DAC

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 2006 [1]). The difference — approximately 250-fold — arises from the DAC albumin-binding mechanism. Sermorelin, for comparison, has a half-life of ~10–12 minutes [15].

## CJC-1295 with DAC vs Without DAC: Dosing Differences

With DAC (half-life 5.8–8.1 days): once-weekly or biweekly injection in research protocols; tonic GH elevation.

Without DAC / Mod GRF 1-29 (half-life ~30 minutes): multiple daily injections required; discrete pulsatile GH response per injection. This preserves physiologic pulsatility more closely than the tonic with-DAC profile [14].

## Injection Frequency in Research Protocols

CJC-1295 with DAC was studied at single-injection and once-weekly or biweekly SC injection schedules [1, 2]. No peer-reviewed comparative cycling data (5 on / 2 off versus continuous) has been published in humans.

## Cycling Protocols in the Literature

Published research protocols run from single-dose PK characterization to 49-day continuous administration. The Teichman 2006 trial ran to 49 days; the GHRH-knockout mouse study used five continuous weeks [1, 4]. No peer-reviewed comparative cycling data exists in humans.

## Fasted vs Fed Administration

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

## Reconstitution and Storage

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.

## References

[1] Teichman SL, et al. J Clin Endocrinol Metab. 2006;91(3):799-805. https://pubmed.ncbi.nlm.nih.gov/16352683/
[2] Ionescu M, Frohman LA. J Clin Endocrinol Metab. 2006;91(12):4792-7. https://pubmed.ncbi.nlm.nih.gov/17018654/
[3] Jetté L, et al. Endocrinology. 2005;146(7):3052-8. https://pubmed.ncbi.nlm.nih.gov/15817669/
[4] Alba M, et al. Am J Physiol Endocrinol Metab. 2006;291(6):E1290-4. https://pubmed.ncbi.nlm.nih.gov/16822960/
[10] Andersen NB, et al. Growth Horm IGF Res. 2001;11(5):266-72. https://pubmed.ncbi.nlm.nih.gov/11735244/
[11] Aagaard NK, et al. Growth Horm IGF Res. 2009;19(5):426-31. https://pubmed.ncbi.nlm.nih.gov/19231263/
[14] Jetté L, et al. [DAC/no-DAC structural data.] Endocrinology. 2005;146(7):3052-8. https://pubmed.ncbi.nlm.nih.gov/15817669/
[15] Jetté L, et al. [Sermorelin half-life.] Endocrinology. 2005;146(7):3052-8. https://pubmed.ncbi.nlm.nih.gov/15817669/

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A letterpress monograph on the GHRH analog CJC-1295 — with-DAC and without, hand-set from the peer-reviewed record, no clinic, no counter.