CJC-1295 with DAC

The abbreviation DAC stands for Drug Affinity Complex and refers to a maleimide group on the molecule. In plasma it forms a firm, covalent bond with albumin. The peptide thus rides piggyback on the transport protein, and its half-life grows from hours to several days. That is what sets CJC-1295 with DAC apart from the variant without DAC (Mod GRF 1-29), which is broken down quickly.

The basic building block in both cases is a modified analogue of natural GHRH (1-29). It docks onto GHRH receptors in the anterior pituitary and triggers the release of growth hormone there. Thanks to the albumin bond the stimulus persists for days: in studies, growth hormone and IGF-1 stayed elevated for up to six days after a single administration.

This fundamentally changes the pattern of release:

• without DAC: a short pulse, then a return to baseline
• with DAC: a persistently raised GH level over several days

For questions in which a steadily activated growth hormone axis is to be observed, the DAC variant is therefore the tool of choice. The downside is the loss of the natural pulse sequence with which the body normally releases growth hormone. The literature discusses this trade, sustained action against rhythm, as a balance between the two variants. When you choose between them, you are deciding about the time profile, not the mechanism.

Clinical data on the DAC form extend to 49 days of observation and describe pharmacokinetics as well as the course of GH and IGF-1 in healthy adults.

The substance stimulates the body's own release of growth hormone rather than supplying it. Unlike the short-acting variant, however, the stimulus persists for days, and the feedback loop works against a constantly raised level. Long-term human studies are missing; the assessment rests on short studies and anecdotal reports.

• Injection site: redness, a feeling of pressure or a brief irritation after subcutaneous administration, the most frequent observation.
• Typical of growth hormone: water retention plus numb or tingling hands as in carpal tunnel syndrome. Because of the sustained GH elevation these effects can be stronger than with short-acting GHRH analogues.
• Glucose metabolism: a persistently raised GH level can lift fasting blood sugar and lower sensitivity to insulin in studies.
• Loss of pulsatility: uniform rather than rhythmic stimulation is regarded in the literature as a drawback compared with the natural pattern.

This summary is no substitute for medical advice.

• Prolonged Stimulation of GH and IGF-I by CJC-1295 - pharmacokinetics and the course of growth hormone and IGF-1 in healthy adults over an observation period of up to 49 days.
• Human GHRF-albumin bioconjugates - identification of CJC-1295 - how the albumin bond comes about and that the conjugate activates the pituitary GHRH receptor.