RESEARCH CONTEXT
All dose parameters on this page are derived from preclinical and published Phase I/II-context research data. They are research-context parameters, not clinical guidance for human use. Neither CJC-1295 nor ipamorelin is FDA-approved.
Dose Ranges Studied in Preclinical and Human Protocols
CJC-1295 ipamorelin dosage parameters in the published literature span a wide range by species, route, and study objective. No CJC-1295/ipamorelin combination dosing study in humans has been published; the human dose data for CJC-1295 come from the Phase I/II-context single-compound trials, and the ipamorelin dose data come primarily from rat and swine preclinical studies and Phase I human safety data.
| Compound | Species | Dose Range | Route | Reference |
|---|---|---|---|---|
| CJC-1295 (DAC) | Human | 60–90 µg/kg | Subcutaneous | [1] |
| CJC-1295 | Mouse (GHRH-KO) | 2 µg/day | Injection | [5] |
| Ipamorelin | Rat | Dose-dependent series | Subcutaneous | [4] |
| Ipamorelin | Rat | 100 µg/kg 3x daily | Subcutaneous | [8] |
| Ipamorelin | Rat | 0.5 mg/kg/day × 12 weeks | Subcutaneous | [9] |
| Ipamorelin | Rat | 0.01–1 mg/kg 4x daily | Intravenous | [10] |
CJC-1295 and Ipamorelin Half-Life
CJC-1295 without DAC approximates the pharmacokinetic profile of native GRF(1-29), which has a plasma half-life below 10–13 minutes due to rapid DPP-IV N-terminal cleavage.[16] CJC-1295 with the DAC albumin-bioconjugation modification has a plasma half-life of approximately 6–8 days in humans, confirmed by the sustained IGF-1 elevation persisting beyond 14 days from a single dose[1] and by plasma detection beyond 72 hours post-single-subcutaneous-dose in rats.[2]
Ipamorelin's plasma half-life in rodents is approximately 2 hours, estimated from pharmacokinetic excretion studies showing 5-fold lower plasma clearance than GHRP-6 and 60–80% of administered dose recoverable as intact peptide from bile and urine.[7] No formally published human pharmacokinetic data exist for ipamorelin's half-life in vivo.
EST. 04 — HALF-LIFE COMPARISON: NATIVE GHRH / NO-DAC / DAC
Injection Frequency in Study Protocols
Research protocols vary by compound form and study objective. CJC-1295 with DAC has been studied at once-weekly or less frequent dosing intervals in human Phase I/II-context studies, consistent with its multi-day half-life.[1] CJC-1295 without DAC has been proposed in research settings at once-to-twice daily subcutaneous injection based on its shorter half-life approximating native GRF(1-29), though published data for this frequency in human subjects are limited.
Ipamorelin has been studied at 1–3 daily doses in animal models: three-times-daily subcutaneous injection was the primary protocol in the bone formation and glucocorticoid-counteraction studies,[8] and four-times-daily IV dosing was used in GI motility protocols.[10] Human combination injection frequency protocols have not been published in peer-reviewed literature.
Fasting State and Injection Timing in Study Protocols
Research protocols typically specify fasted-state administration to minimize somatostatin-mediated GH blunting. Food intake elevates insulin; elevated insulin triggers hypothalamic somatostatin release; somatostatin suppresses pituitary GH secretion, reducing the GH pulse amplitude produced by GHRH-axis or ghrelin-axis stimulation. In a 5-day fast study in men, GH pulse frequency increased from 5.8 to 9.9 pulses per 24 hours (p=0.028) and 24-hour GH concentration rose from 2.82 to 8.75 µg·min/mL (p=0.0002), with elevated free fatty acids and reduced insulin identifying somatostatin suppression as the primary mechanism.[11]
The circadian link between slow-wave sleep (SWS) and the largest endogenous GH pulse of the day is a relevant timing context. Ghrelin administration to human subjects (4 × 50 µg IV boluses over 3 hours) enhanced slow-wave sleep and delta-wave activity,[12] suggesting ghrelin-receptor agonism may amplify the nocturnal GH/sleep coupling. Timing protocols for ipamorelin specifically in human subjects have not been published.
Time Course of Effects in Research Models
CJC-1295 produced sustained GH elevations detectable within hours of injection in human Phase I/II-context trials; IGF-1 elevation was confirmed at one week post-dose.[1] Sustained IGF-1 elevation persisted for up to 28 days post-dose with the DAC form. Ipamorelin's acute GH pulse peaks approximately 15–30 minutes post-injection in rodent models based on GH secretagogue pharmacodynamic literature, consistent with its ~2-hour half-life and GHS-R1a pulsatile-release mechanism.
For the GH-axis endpoints in human studies (CJC-1295 alone), measurable elevation appears within the first week. For downstream body composition and bone endpoints in animal studies, measurable changes have been documented at 4–12 weeks.[4][8][9]
Reconstitution and Handling in Research Settings
Lyophilized peptide vials are typically reconstituted with bacteriostatic water (0.9% benzyl alcohol) in research settings. Standard reference protocols add bacteriostatic water slowly down the vial wall — not directly onto the lyophilized pellet — to avoid agitation-induced aggregation that accelerates peptide degradation.
Reconstituted aqueous peptide solutions degrade via asparagine deamidation; degradation products may be 25–500-fold less potent than intact peptide. The stability literature specifies lyophilized vials stable at −20°C for months; reconstituted solutions stored at 2–8°C should be used within the window specified by peptide stability characterization data. Agitation accelerates aggregation. GRF analogs undergo DPP-IV cleavage in plasma; the DAC form was engineered specifically to resist this pathway, but reconstituted solution stability precedes in vivo metabolism.