Dosage research on CJC-1295 No DAC

Preclinical research dose ranges

In published preclinical research on CJC-1295 No DAC and on the broader sermorelin / GHRH(1-29) family, administered dose ranges in rodent studies have most commonly fallen in the 1 to 50 microgram per kilogram range delivered subcutaneously. The pharmacology characterising the GHRH-receptor activation and downstream GH-pulse generation has used doses in this range across rat and mouse studies in the published endocrinology literature.

Human pharmacology of the parent CJC-1295 (DAC-bearing variant) used doses of 30, 60, and 250 micrograms per kilogram subcutaneously in the Teichman and colleagues 2006 trial, with sustained GH and IGF-I elevation across multi-day observation windows. The No-DAC variant returns to a short circulating half-life and produces a pulsatile rather than sustained GH-release pattern, which changes the dose-response characteristics relative to the DAC variant.

The Ionescu and Frohman 2006 work characterised the pulsatile GH-release pattern under continuous CJC-1295 stimulation, providing the published mechanistic backing for the per-pulse GH-amplitude framing of dose response. Investigators reading the published CJC-1295 literature should distinguish between work on the DAC-bearing variant (long sustained release) and the No-DAC variant (short pulsatile release) when interpreting dose-response data.

Dose-response considerations from the published literature

The published CJC-1295 literature has reported dose-response characteristics that scale GH-pulse amplitude with administered dose across the microgram-per-kilogram range in rodent pharmacology. The DAC-bearing variant produces sustained GH and IGF-I elevation through covalent attachment to serum albumin via a maleimide-lysine linker; the No-DAC variant returns to a pulsatile profile more closely resembling endogenous GHRH-driven release.

No Phase 1 dose-ranging trial of CJC-1295 No DAC specifically (as distinct from the DAC-bearing variant) has appeared in the indexed clinical-trial literature. The pharmacokinetic and dose-response characterisation in the published work used the DAC-bearing variant, and inference to the No-DAC variant requires accounting for the difference in plasma persistence. The research community continues to rely on the rodent pharmacology and on the DAC-variant clinical data for dose-design inference.

Reconstitution math and per-vial dose calculation

A 10 mg lyophilised CJC-1295 No DAC vial reconstituted with 2 mL of bacteriostatic water yields a stock concentration of 5 mg per mL. From this stock, a research aliquot of 0.1 mL contains 500 micrograms; an aliquot of 0.02 mL contains 100 micrograms. Researchers working with the microgram-per-kilogram dose ranges reported in published rodent pharmacology further dilute the stock to a working concentration appropriate to the model and the body weight of the animal subject. Refrigerated storage at 2 to 8 degrees Celsius, protected from light, is the standard handling practice reported across the rodent in-vivo work.

Research-protocol design considerations

Protocol-design choices in the published CJC-1295 literature reflect several recurring considerations. Dose selection anchors at the 1 to 50 microgram per kilogram range in rodent pharmacology, with the choice of point within that range determined by whether the endpoint is GH-pulse-amplitude characterisation, IGF-I time-course measurement, or pharmacokinetic profiling.

Route of administration in the published rodent work most commonly uses subcutaneous injection. Intravenous administration appears in pharmacokinetic studies. The choice between DAC-bearing and No-DAC variant is a primary protocol-design consideration: investigators wanting sustained GH and IGF-I elevation choose the DAC-bearing variant, while investigators wanting a pulsatile release pattern that more closely resembles endogenous GHRH-driven release choose the No-DAC variant.

Stacking with Ipamorelin (a selective ghrelin-receptor agonist) is a protocol-design pattern that appears in the research-community discussion literature and in some published combined-administration pharmacology. The mechanistic rationale is that GHRH-receptor activation and ghrelin-receptor activation each drive GH release through independent endogenous pathways, and combined administration produces a larger GH-pulse amplitude than either compound alone.

References

1. Jetté L et al. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats. Endocrinology, 2005. [PMID 15817669]
2. Teichman SL et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295. Journal of Clinical Endocrinology and Metabolism, 2006. [PMID 16352683]
3. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295. Journal of Clinical Endocrinology and Metabolism, 2006. [PMID 17018654]
4. Sackmann-Sala L et al. The growth hormone receptor and the role of growth hormone in clinical pharmacology. Annual Review of Pharmacology and Toxicology, 2014. [PMID 24160708]
5. Bowers CY. Growth hormone-releasing hormone and growth hormone-releasing peptide as therapeutic agents. Journal of Pediatric Endocrinology and Metabolism, 1997. [PMID 9238854]