What it is: A synthetic version of the hormone that signals your pituitary gland to release growth hormone, available in a short-acting form and a long-acting albumin-binding form.
Research suggests: Human studies confirm it reliably increases GH and IGF-1 levels; the combination with a GHRP like ipamorelin is among the most studied GH optimization approaches.
Best for: Growth hormone optimization researchers
Key thing to know: The DAC version has an approximately 8-day half-life; the non-DAC version (Modified GRF 1-29) produces shorter GH pulses more similar to natural rhythms.
What is CJC-1295?
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) , the signal your hypothalamus naturally sends to your pituitary gland to trigger growth hormone release. It comes in two distinct forms with meaningfully different pharmacological profiles: CJC-1295 without DAC (also called Modified GRF 1-29), which produces a short-acting GH pulse lasting 30 minutes to a few hours, and CJC-1295 with DAC (Drug Affinity Complex), which binds to albumin in the bloodstream to extend its half-life to approximately eight days.
Researchers have studied CJC-1295 for sustained elevation of growth hormone and IGF-1 levels, body composition improvement, fat reduction, and recovery , most commonly in combination with Ipamorelin, where the two compounds work through complementary receptor pathways to amplify GH output beyond what either achieves alone.
How it works.
Your hypothalamus naturally releases GHRH in pulses to signal the pituitary gland to produce and secrete growth hormone. CJC-1295 mimics this signal by binding to GHRH receptors on the pituitary, triggering GH production through the body's own gland , preserving the normal feedback mechanisms that regulate how much GH is produced.
The without-DAC version (Modified GRF 1-29) closely mirrors the natural GHRH pulse: it binds, triggers a GH release event, and is then cleared from the body relatively quickly. This is the form typically paired with Ipamorelin , the Ipamorelin triggers the GHS-R receptor while CJC-1295 without DAC triggers the GHRH receptor simultaneously, producing amplified GH output through two distinct pathways at once.
The with-DAC version works differently: the Drug Affinity Complex modification allows it to reversibly bind to albumin (the most abundant protein in blood), which acts as a carrier and dramatically slows its breakdown. Think of CJC-1295 without DAC as sending a strong GH signal with each injection, and the DAC version as installing a slow-release signal that keeps the pituitary producing GH continuously throughout the week from a single injection.
What the research shows.
Published human pharmacokinetic and pharmacodynamic studies on CJC-1295 with DAC document significant and sustained elevation of GH and IGF-1 levels. A key published study demonstrated dose-dependent increases in mean 24-hour GH concentrations and IGF-1 levels that persisted for up to 28 days following a single injection , a pharmacological profile unlike most compounds in this class. This makes CJC-1295 with DAC one of the more clinically documented GH secretagogues in terms of direct, measurable hormone effects in humans.
However, the published evidence base focuses primarily on GH and IGF-1 level changes rather than downstream clinical outcomes. Large long-term randomized controlled trials examining body composition, recovery markers, aging endpoints, or clinical outcomes in general healthy populations have not been conducted. The combination research with Ipamorelin is well-documented in practice but the published RCT base for the combination is limited compared to the individual compound data.
The evidence profile is Moderate: human data confirming the primary pharmacological effect (GH and IGF-1 elevation) is published and meaningful, but the connection between these hormonal effects and specific clinical outcomes in diverse populations has not been established at the level of large-scale trials.
Biomarkers to review first.
Research protocols for CJC-1295 typically reference the following biomarkers as baseline context. Testing these before exploring this peptide gives you and your healthcare provider the most relevant starting information.
What it's commonly researched with.
CJC-1295 is most extensively studied in combination with Ipamorelin, where the GHRH-receptor and GHS-receptor pathways work in concert. This pairing is one of the most frequently cited combinations in GH secretagogue research literature. The entries below represent what appears in the research literature , not combinations to pursue without clinical supervision.