CJC-1295
CJC-1295 (with & without DAC)
A long-lasting growth hormone releasing hormone analog available in two versions for flexible dosing and sustained GH elevation.
CJC-1295 is a synthetic peptide that mimics growth hormone releasing hormone (GHRH), the natural signal your brain sends to tell your pituitary gland to produce growth hormone. Your hypothalamus normally produces GHRH in short bursts, but it breaks down in minutes. CJC-1295 is engineered to last much longer in your body, giving your pituitary gland a prolonged instruction to keep releasing growth hormone. It was developed by ConjuChem Biotechnologies and reached Phase 2 clinical trials for lipodystrophy and growth hormone deficiency before development was discontinued. Neither version is FDA approved.
There are two versions of this peptide. CJC-1295 with DAC (Drug Affinity Complex) has a special attachment that lets it bind to albumin, a protein in your blood that acts like a protective taxi. This shields the peptide from being broken down and extends its working time to six to eight days per injection. Think of it like a slow-release capsule: you inject far less often and your growth hormone stays elevated for days. It is best for people who want convenience and fewer injections.
CJC-1295 without DAC, also called Mod GRF 1-29 or Modified GRF, lacks this protective attachment. It has a much shorter working time of about thirty minutes to two hours, which means you need to inject daily. However, this creates a pattern of growth hormone release that closely matches your body's natural rhythm of peaks and valleys. It is the most popular GHRH analog because it is more stable than Sermorelin, has a cleaner side effect profile, and preserves the natural pulsatile pattern. This is why it became the standard choice for combining with Ipamorelin.
How It Works
CJC-1295 is a modified version of the first 29 amino acids of natural GHRH, which contain everything needed to signal the pituitary gland to release growth hormone. When CJC-1295 enters your bloodstream, it travels to the pituitary gland and binds to GHRH receptors on cells called somatotrophs. These are the cells that manufacture and release growth hormone. The binding triggers a chain of signals inside the cell involving G proteins, cyclic AMP, and protein kinases, ultimately causing those cells to release growth hormone into your bloodstream.
That growth hormone then travels to your liver, where it stimulates the production of IGF-1 (insulin-like growth factor 1). IGF-1 is responsible for many of the effects people associate with growth hormone, including muscle growth, fat loss, and tissue repair. Natural GHRH has a working life of only a few minutes, but CJC-1295 without DAC extends this to thirty minutes to two hours, creating a sharp pulse of growth hormone release that then clears, preserving the natural rise-and-fall pattern.
CJC-1295 with DAC works differently because the Drug Affinity Complex allows it to attach to albumin in your blood. Albumin protects whatever it carries from being broken down. With DAC attached, CJC-1295 stays active for six to eight days, creating sustained elevation of growth hormone rather than pulses. This is convenient because you only inject once or twice per week, but it is not how your body naturally operates. Human studies showed that a single injection increased growth hormone two to ten times above baseline, with IGF-1 increasing 1.5 to 3 times for nine to eleven days.
Potential Benefits
Increased Growth Hormone Production
Both versions raise your overall growth hormone output significantly. The with DAC version creates sustained elevation over days, while the without DAC version creates higher peaks followed by return to baseline. Clinical data showed growth hormone levels increasing two to ten times above baseline, with IGF-1 levels rising 1.5 to 3 times and remaining elevated for over a week after a single injection.
Muscle Growth and Recovery
Growth hormone and IGF-1 both support protein synthesis, the process your body uses to build new muscle tissue. Higher levels make it easier to build and maintain muscle. Users report improved recovery between training sessions, reduced muscle soreness, and better ability to add lean mass over time when combined with consistent resistance training and adequate protein intake.
Fat Loss
Growth hormone promotes lipolysis, which is the breakdown of stored fat for energy. This effect is particularly noticeable in visceral fat, the deep fat around your organs that is most associated with health risks. Studies on growth hormone secretagogues consistently show improvements in body composition with reduced fat mass.
Improved Sleep
GHRH has direct effects on sleep beyond its role in growth hormone release. Research shows that GHRH increases the duration and intensity of deep slow-wave sleep, which is the most restorative phase of sleep. Many users report falling asleep faster, sleeping more deeply, and waking up feeling more rested, often within the first one to two weeks of use.
Tissue Repair and Recovery
Growth hormone stimulates collagen synthesis and cellular repair throughout the body. This can translate to faster healing from injuries, improved skin quality and elasticity, and better joint health over time. These effects develop gradually and become more noticeable with consistent use over several months.
Bone Density Support
Long-term growth hormone optimization supports bone mineral density. This is particularly relevant for older adults experiencing age-related decline in both growth hormone and bone health, as maintaining adequate growth hormone levels helps preserve skeletal strength.
What the Research Shows
Teichman and colleagues published two randomized, placebo-controlled, double-blind trials in the Journal of Clinical Endocrinology and Metabolism in 2006, studying CJC-1295 with DAC in healthy adults aged 21 to 61. After a single injection, growth hormone increased two to ten fold for more than six days, and IGF-1 increased 1.5 to 3 fold for nine to eleven days. The half-life was estimated at 5.8 to 8.1 days. After multiple doses, IGF-1 remained above baseline for up to 28 days with evidence of cumulative effect. The peptide was well tolerated at doses of 30 or 60 mcg/kg with no serious adverse reactions.
Ionescu and Frohman published a 2006 study in the same journal showing that CJC-1295 preserves the natural pulsatile pattern of growth hormone secretion even during continuous stimulation. This was important because it suggested the peptide works with your body's normal rhythm rather than overriding it. Alba and colleagues published a 2006 study in the American Journal of Physiology showing that once-daily CJC-1295 administration normalized growth patterns in mice lacking normal GHRH signaling, with treated animals reaching normal body weight and length.
CJC-1295 reached Phase 2 clinical trials for lipodystrophy and growth hormone deficiency. Development was discontinued after one trial subject died. The attending physician concluded the death was likely caused by undiagnosed coronary artery disease unrelated to the peptide, but development was not resumed. When combined with a GHRP like Ipamorelin, research shows the combination can produce 77 to 225 percent greater growth hormone release than either peptide alone, because they work through different receptor pathways that amplify each other.
What to Know
Injection site reactions including redness and irritation, water retention, flushing or warmth after injection, transient tingling or numbness, and headache are the most frequently reported side effects with both versions of CJC-1295.
The with DAC version may produce more pronounced water retention and side effects that last longer and are harder to manage because of the long half-life. Receptor desensitization is possible with continuous use. The without DAC version has side effects that clear quickly due to its short half-life, making dose adjustment easier if problems occur.
Cardiovascular effects including flushing and transient low blood pressure have been reported rarely. The FDA has raised concerns about potential immunogenicity with CJC-1295. Do not use if you have active cancer, diabetic retinopathy, or are pregnant or breastfeeding. Use caution with diabetes, cardiovascular disease, or history of carpal tunnel syndrome.
Research References
Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults
Teichman SL, et al. · Journal of Clinical Endocrinology & Metabolism · 2006
Two randomized, placebo-controlled, double-blind trials in healthy adults aged 21 to 61 showed CJC-1295 with DAC increased growth hormone 2 to 10 fold for over 6 days, increased IGF-1 1.5 to 3 fold for 9 to 11 days, and demonstrated cumulative effects with repeated dosing. Well tolerated with no serious adverse reactions.
View StudyPulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog
Ionescu M, Frohman LA · Journal of Clinical Endocrinology & Metabolism · 2006
Demonstrated that CJC-1295 preserves the natural pulsatile pattern of growth hormone secretion even during continuous stimulation, suggesting the peptide works with the body's natural rhythm rather than overriding it.
View StudyOnce-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse
Alba M, et al. · American Journal of Physiology: Endocrinology and Metabolism · 2006
Studied CJC-1295 in mice lacking normal GHRH signaling and found that once-daily administration normalized growth patterns, with treated animals reaching normal body weight and length.
View Study