CJC-1295 with DAC is a synthetic peptide designed to stimulate your pituitary gland to produce more growth hormone. What sets it apart from similar peptides is the “DAC” portion, a chemical modification that extends its active life in the body from roughly 30 minutes to about 6 to 8 days. That dramatically longer duration means fewer injections and a sustained elevation in growth hormone levels, which is why it has attracted significant interest in anti-aging, body composition, and recovery circles. It is not FDA-approved for human use.
How the DAC Modification Works
CJC-1295 on its own is a modified version of growth hormone-releasing hormone (GHRH), the natural signal your brain sends to trigger growth hormone production. Without any modification, this type of peptide breaks down quickly in the bloodstream. Enzymes chew it up, and your kidneys clear it out, giving it a useful life of only about 30 to 60 minutes.
The Drug Affinity Complex, or DAC, solves this problem through a clever piece of biochemistry. It’s a small chemical tag attached to the peptide that reacts with albumin, the most abundant protein in your blood. Specifically, the DAC contains a reactive group (a maleimide) that forms a permanent covalent bond with a particular spot on albumin called cysteine-34. Once locked onto albumin, the peptide essentially hitchhikes on a molecule your body already keeps around for a long time. Albumin’s natural half-life in humans is about 15 days, so the attached peptide avoids being broken down by enzymes or filtered out by the kidneys. The bond is permanent, meaning the peptide doesn’t need to detach from albumin to do its job. It remains biologically active while riding along.
This reaction is highly selective for albumin over other blood proteins because albumin exists at far higher concentrations in plasma and because its cysteine-34 sits in a uniquely reactive chemical state compared to similar molecules floating around in your blood.
What It Does to Growth Hormone Levels
A common concern with sustained-release growth hormone stimulators is that they might flatten the body’s natural pulsatile pattern of GH release. Your pituitary normally releases growth hormone in bursts, especially during deep sleep, rather than at a steady trickle. Research published in The Journal of Clinical Endocrinology & Metabolism found that CJC-1295 preserved this pulsatile pattern. The frequency and size of growth hormone pulses stayed the same after administration.
What did change significantly was the baseline level between pulses. Trough GH levels increased 7.5-fold, and mean overall GH levels rose by 46%. IGF-1, the downstream hormone that mediates many of growth hormone’s effects on tissues, increased by 45%. This pattern is sometimes called “GH bleed,” referring to the elevated baseline between pulses. The practical result is that your body maintains its natural rhythm of GH spikes but operates at a much higher floor level around the clock. That sustained elevation of trough levels appears to be the primary driver behind the increase in IGF-1.
Potential Benefits
Because CJC-1295 with DAC raises growth hormone and IGF-1 levels, its expected effects mirror what elevated GH does in the body. These include supporting lean muscle development through increased protein synthesis, enhancing fat metabolism by promoting the use of stored fatty acids for energy, and improving sleep quality by reinforcing the deep sleep cycles where GH release naturally peaks. Recovery from exercise or injury may also improve, since growth hormone plays a direct role in tissue repair.
These benefits overlap with what you’d expect from synthetic growth hormone injections, but through a different mechanism. Rather than injecting GH directly, CJC-1295 with DAC prompts your own pituitary to make more of it. This distinction matters because it means the body’s feedback systems remain partially engaged, and the GH produced is your own, released in your natural pattern (albeit at higher levels).
How It Compares to CJC-1295 Without DAC
The version without DAC, sometimes sold as “Mod GRF 1-29,” has a half-life of roughly 30 to 60 minutes. That means it needs to be injected multiple times per day to have a meaningful effect, and each injection produces a short, sharp spike in growth hormone rather than a sustained elevation. People who use the non-DAC version typically inject it two or three times daily, often alongside a second peptide.
CJC-1295 with DAC, by contrast, is typically administered once per week at around 600 micrograms, injected subcutaneously on an empty stomach at least two to three hours after the last meal of the day. The tradeoff is control: the non-DAC version gives you more precise, short-lived pulses you can time around training or sleep, while the DAC version provides a constant background elevation with less hassle.
Pairing With Other Peptides
CJC-1295 is frequently combined with growth hormone-releasing peptides (GHRPs) like GHRP-6 or GHRP-2. The logic behind this pairing is that the two peptide types work through completely different receptor pathways. CJC-1295 activates the GHRH receptor, while GHRPs act on the ghrelin receptor. When both pathways are stimulated simultaneously, the result can be synergistic rather than simply additive, increasing both the amplitude and frequency of growth hormone pulses from the pituitary. This stacking approach is common in peptide therapy protocols, though it adds complexity and additional side effect considerations.
Side Effects and Risks
The side effects of CJC-1295 with DAC are largely those associated with elevated growth hormone levels in general. Common ones include water retention (swelling in hands and feet), joint pain, tingling or numbness in the extremities, and flushing or warmth at the injection site. The FDA has specifically flagged increased heart rate and systemic vasodilatory reactions (a sudden drop in blood pressure from blood vessel dilation) as serious adverse events associated with CJC-1295.
Longer-term risks mirror those of sustained growth hormone elevation from any source. Elevated GH can impair insulin sensitivity and push blood sugar levels higher, potentially increasing the risk of developing type 2 diabetes over time. Prolonged supraphysiological growth hormone levels have also been linked to joint problems, and in the context of synthetic GH use, more serious concerns including abnormal tissue growth have been reported. The sustained nature of the DAC version means these risks are present continuously rather than in brief windows, which is worth considering.
Regulatory Status
CJC-1295 with DAC is not approved by the FDA for any medical use. The FDA has placed it on a list of bulk drug substances that may present significant safety risks when used in compounding, citing concerns about immunogenicity (the possibility that the body mounts an immune response against the peptide), impurity control during manufacturing, and the limited clinical data available. Available research in humans is sparse, and most of what circulates about dosing and benefits comes from early-phase trials, animal studies, or anecdotal reports from the peptide therapy community. It is a research chemical, not a regulated medication, and quality control varies widely between suppliers.