CJC-1295 and Ipamorelin work on different receptors but converge on the same outcome: increased GH pulse from the pituitary. This complementary mechanism is why they are so commonly stacked.
| Dimension | CJC-1295 | Ipamorelin |
|---|---|---|
| Receptor target | GHRH receptor (GHRHR) — the same receptor that endogenous GHRH binds. Acts upstream on the pituitary to prime GH release. | Ghrelin receptor (GHSR-1a) — different mechanism. Mimics ghrelin's GH-releasing action without ghrelin's other effects. |
| Primary action | Amplifies the baseline GH pulse by increasing pituitary sensitivity to GHRH. Does not trigger a pulse on its own — enhances the natural cycle. | Triggers a GH pulse. Acts independently of GHRH signal. Can stimulate release even without a concurrent GHRH signal. |
| Half-life | ~30 minutes (no-DAC form). Modified at positions 2, 8, 15, 27 vs native GHRH to improve stability vs. native GHRH 1–29 (~7 min). | ~2 hours. Longer than GHRPs like GHRP-2 and GHRP-6. Better plasma stability than earlier secretagogues. |
| Selectivity | Selective for GHRH receptors. Does not meaningfully stimulate cortisol or prolactin at research doses in animal models. | Highly selective. Does not significantly stimulate cortisol, prolactin, or ACTH at research doses. This selectivity is the defining feature vs. older GHRPs. |
| Why stack together? | Primes the pituitary via GHRH pathway. The synergy with a GHRP like Ipamorelin produces a larger GH pulse than either alone. | Triggers the pulse via ghrelin pathway. When combined with CJC-1295, amplifies total GH output by acting on a second receptor simultaneously. |
| Dimension | CJC-1295 | Ipamorelin |
|---|---|---|
| Evidence base | Limited preclinical + early human Fewer published studies than Ipamorelin's clinical data. Modified GRF compounds have a smaller literature than native GHRH analogs. Some human pharmacokinetic data published (Ionescu 2006). | Phase 2 human data exists Ipamorelin reached Phase 2 clinical trials (Helsinn/Novo Nordisk for postoperative GI dysfunction). Human pharmacokinetic and GH stimulation data are available. Most human-studied GHRP in this category. |
| Human clinical trials | Limited Small human pharmacokinetic studies exist (e.g., Ionescu et al., 2006 — dose-dependent GH increases in healthy adults). No large-scale efficacy RCTs published. | Phase 2 completed Completed Phase 2 for postoperative ileus (Helsinn). Phase 2 for obesity-related GH deficiency. Did not advance to Phase 3 for those indications. Human safety and PK data are available. |
| Divergence from research | High Community dosing (100–300 mcg daily, SQ) is not derived from published human clinical data. Extrapolated from animal studies and anecdotal reports. No human dose-response curve published for these protocols. | Moderate Phase 2 doses (200–300 mcg) overlap with community protocols, though the indication (postoperative ileus) is different from community use cases (GH optimization, body composition). Closer alignment than CJC-1295. |
| IGF-1 effects | Human data shows sustained IGF-1 elevation with repeated dosing. The Ionescu study showed dose-dependent IGF-1 increases 7 days post-injection. Longer half-life contributes to this. | GH pulse stimulation confirmed in humans. IGF-1 response less characterized in community-relevant dosing protocols. Shorter half-life means more transient effect per administration. |
| Dimension | CJC-1295 | Ipamorelin |
|---|---|---|
| Common ref. amount | 100–300 mcg per administration. Community: typically before sleep to align with natural GH pulse. | 200–300 mcg per administration. Same timing pattern: before sleep or fasted state. |
| Community frequency | Daily (when used with Ipamorelin in stack). Some 5 days on / 2 days off protocols discussed in forums. No research basis for cycling. | Daily in stack protocols. Sometimes 1–3× daily in community use, though human PK data from trials suggests once daily dosing. |
| Typical stack | Almost always stacked with Ipamorelin or another GHRP. Rarely used alone in community protocols due to its amplifying (rather than triggering) mechanism. | Frequently paired with CJC-1295. Can be used alone. Most-cited "clean" GHRP due to selectivity for GH without cortisol/prolactin effects. |
| Regulatory status 2026 | Not part of the July 2026 PCAC review. Named in the 2026 HHS reconsideration; no vote yet. Currently sold RUO. | Also not part of the July 2026 review. Status pending a future PCAC round. Currently sold RUO. |
Lone Star Peptide Co. carries the CJC-1295 + Ipamorelin research blend — batch-specific COAs, third-party testing, and same-day domestic shipping from Houston, TX.