CJC-1295 is a lab-made copy of a natural hormone called GHRH — growth-hormone-releasing hormone. GHRH is the body's own "release growth hormone now" signal, sent from the brain to the pituitary gland. CJC-1295 mimics that signal, but with one engineered twist that makes it last far longer than the real thing. The single most important thing to understand about it is a fork in the road called DAC.
In plain terms: it's a long-lasting copy of your body's own "make growth hormone" message — and it comes in two versions that behave nothing alike.
The DAC fork — read this first
"CJC-1295" can mean two very different molecules, and confusing them is the most common mistake people make:
- With DAC (Drug Affinity Complex): a chemical add-on that latches the peptide onto albumin, an abundant, long-lived blood protein. Hitched to albumin, it's shielded from rapid breakdown, so its half-life is days.
- Without DAC (usually called mod GRF 1-29): no albumin anchor, so it clears in minutes.
Same base peptide, completely different duration — which is why any half-life number for "CJC-1295" is meaningless unless the form is specified (full breakdown, curve).
What it is
CJC-1295 is a modified fragment of GHRH — specifically the first 29 amino acids, GHRH(1-29), with a few substitutions that resist breakdown, plus (in the DAC form) the albumin anchor1. As a GHRH analog it pulls the GHRH lever on the growth-hormone system — the opposite lever from the ghrelin/GHS receptor that ipamorelin uses.
What the studies actually found
CJC-1295 stands out among research peptides because it has genuine human pharmacokinetic data — studies that measured what it does to hormone levels in people:
| Study | Model | Key result | Year |
|---|---|---|---|
| Teichman et al.1 | Human (healthy adults, DAC form) | A single injection raised growth hormone 2–10× for 6+ days and IGF-1 1.5–3× for 9–11 days; measured half-life 5.8–8.1 days | 2006 |
| Ionescu & Frohman2 | Human (healthy men, DAC form) | Even under constant stimulation, growth hormone kept its natural pulses; trough levels rose ~7.5× and 24-hour output ~46% | 2006 |
| FDA 503A action3 | US regulatory | CJC-1295 placed on the 2023 interim compounding review list (Category 2); status still evolving | 2023 |
Two honest points about that top row. First, it's a real, encouraging human result — a days-long rise in growth hormone from one shot. Second, it measured hormone levels, not a health outcome. "IGF-1 went up for 11 days" is not the same as "it built muscle" or "it was safe long-term." Those trials were never completed.
The Ionescu & Frohman finding is a nice bit of biology worth keeping: even when CJC-1295 keeps the "release" signal switched on continuously, the pituitary still fires in natural pulses rather than one flat stream2 — the body's rhythm is preserved.
Why it's paired with ipamorelin
CJC-1295 pulls the GHRH lever; ipamorelin pulls the separate ghrelin lever. Because the two receptors are different and complementary, research studies them together — the idea being that pushing both at once yields a larger, more natural pulse than either alone (the pairing explained). Within its own class, CJC-1295 is most often set against the approved drug tesamorelin (tesamorelin vs CJC-1295).
Regulatory status
CJC-1295 is not an approved medicine. In 2023 the FDA placed it on the Category 2 portion of its interim 503A bulk-substances list for compounding pharmacies3. That status has since been in flux — some peptide nominations were withdrawn in 2024 and the advisory committee scheduled further review — so treat the exact rule as a moving snapshot. This page never discusses sourcing.
Latest research
- The 2006 Teichman and Ionescu–Frohman studies remain the anchor human pharmacokinetic data and are still what any credible half-life figure traces back to12.
- The live story is regulatory: the FDA's compounding review of CJC-1295 and related peptides is the thing most likely to change next3.
- We update this section as new studies report.
The short version
CJC-1295 is a long-acting GHRH copy that tells the pituitary to release growth hormone — and, unusually for a research peptide, it has real human data showing a 6–8 day half-life and days-long IGF-1 rises. But that data is about hormone *levels*, not proven benefits, and it's a research compound, not a medicine. Always pin down DAC vs no-DAC first (here); the class map is in growth-hormone secretagogues explained.