CJC-1295 (with DAC)

What it is

CJC-1295 with DAC is built from a modified fragment of growth hormone-releasing hormone, the same starting point as the short-acting version described separately, but with an added chemical group known as a Drug Affinity Complex, or DAC. That group causes the molecule to bind loosely and reversibly to albumin, the most common protein in blood, which is what gives it a half-life of roughly six to eight days instead of the half hour or so of the unmodified fragment [1].

Because it lasts so much longer, it produces a steadier signal at the pituitary gland compared with the natural, pulsed pattern of growth hormone-releasing hormone. Researchers have specifically studied whether that steadier, longer-lasting signal still produces the body's normal pulsed pattern of growth hormone release, or whether it instead flattens that pattern into a continuous elevation [1][2].

How it is studied

The core human evidence comes from two related clinical pharmacology studies in healthy adults, giving the peptide by injection under the skin at various doses and monitoring blood growth hormone and IGF-1 levels closely over the following days to weeks [1][2]. Researchers used frequent blood sampling to see whether growth hormone was still being released in its normal pulsed rhythm, or continuously, despite the drug's long presence in the bloodstream.

What studies report

• In a healthy-adult trial testing several amounts over 28 to 49 days, CJC-1295 with DAC produced a sustained rise in growth hormone and IGF-1 levels lasting days after a single administration, matching its multi-day half-life. [1]
• In a separate trial with frequent blood sampling, growth hormone continued to be released in its normal pulsed pattern rather than as a flat, continuous elevation, even while background growth hormone levels between pulses rose about 7.5-fold. [2]
• Growth hormone and IGF-1 levels overall rose by roughly 45 to 46 percent on average during continued treatment in the same trial. [2]

What is not known

CJC-1295 with DAC has not been tested in the large, longer-duration randomized trials that would be needed to establish its safety and effectiveness for any specific medical use; the published human data covers healthy volunteers over periods of days to a few months, not long-term or patient-population use. It is not established what happens to pituitary sensitivity with much longer continuous use, or whether the pulsed growth hormone pattern seen in these short studies would hold up over months or years of continued use.

Reported adverse findings

• The published pharmacology trials describe the compound as generally well tolerated over their study periods, with the main reported effects being the intended hormonal changes rather than unexpected adverse events, though these were short studies in healthy volunteers, not long-term safety trials. [1][2]

Regulatory status

No national medicines regulator, including the FDA and Health Canada, has approved CJC-1295 with DAC for any use in humans. It remains a research compound studied only in early-phase human pharmacology studies.